I need help with variables, please

I'm a begginer in C++. I use Microsoft Visual Studio 6.0. I'm writting a 4x4 Sudoku source code and I've named variables like that:
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
I've used while-if-break senteces and I've put printf sentences beetwen them like in the follow code:

Code:

//sudoku.cpp:

#include<stdlib.h>
#include<math.h>
#include<stdio.h>
#include<time.h>

void main(){

srand(time(0));

	int a1;
	int b1;
	int c1;
	int d1;
	int a2;
	int b2;
	int c2;
	int d2;
        int a3;
	int b3;
	int c3;
	int d3;
        int a4;
	int b4;
	int c4;
	int d4;

srand(time(0));

// 1st row

a1=(rand()%4)+1; 

printf("a1 = %d\n",a1);

while((b1!=0)||(b1=a1)){
b1=rand()*5/32768;
if ((b1!=0)&&(b1!=a1)){ 
break;
printf("b1 %d\n",b1);
}}

printf("b1 = %d\n",b1);

while((c1!=0)||(c1=a1)||(c1=b1)){
c1=rand()*5/32768;
if ((c1!=0)&&(c1!=a1)&&(c1!=b1)){
break;
}}
printf("c1 = %d\n",c1);

while((d1!=0)||(d1=a1)||(d1=b1)||(d1=c1)){
d1=rand()*5/32768;
if ((d1!=0)&&(d1!=a1)&&(d1!=b1)&&(d1!=c1)){
break;
}}
printf("d1 = %d\n",d1);


// Column A

while((a2!=0)||(a2=a1)||(a2=b1)){
a2=rand()*5/32768;
if ((a2!=0)&&(a2!=a1)&&(a2!=b1)){
break;
}}

printf("a2 = %d\n",a2);

while((a3!=0)||(a3=a1)||(a3=a2)){
a3=rand()*5/32768;
if ((a3!=0)&&(a3!=a1)&&(a3!=a2)){
break;
}}

printf("a3 = %d\n",a3);


while((a4!=0)||(a4=a1)||(a4=a2)||(a4=a3)){
a4=rand()*5/32768;
if ((a4!=0)&&(a4!=a1)&&(a4!=a2)&&(a4!=a3)){
break;
}}

printf("a4 = %d\n",a4);

// Column D

while((d2!=0)||(d2=c1)||(d2=d1)||(d2=a2)){
d2=rand()*5/32768;
if ((d2!=0)&&(d2!=c1)&&(d2!=d1)&&(d2!=a2)){
break;
}}

printf("d2 = %d\n",d2);


while((d3!=0)||(d3=d1)||(d3=d2)||(d3=a3)){
d3=rand()*5/32768;
if ((d3!=0)&&(d3!=d1)&&(d3!=d2)&&(d3!=a3)){
break;
}}

printf("d3 = %d\n",d3);


while((d4!=0)||(d4=d1)||(d4=d2)||(d4=d3)||(d4=a4)){
d4=rand()*5/32768;
if ((d4!=0)&&(d4!=d1)&&(d4!=d2)&&(d4!=d3)&&(d4!=a4)){
break;
}}

printf("d4 = %d\n",d4);

// 4th row

while((b4!=0)||(b4=a3)||(b4=a4)||(b4=b1)||(b4=d4)){
b4=rand()*5/32768;
if ((b4!=0)&&(b4!=a3)&&(b4!=a4)&&(b4!=b1)&&(b4!=d4)){
break;
}}

printf("b4 = %d\n",b4);

while((c4!=0)||(c4=d3)||(c4=d4)||(c4=c1)||(c4=a4)||(c4=b4)){
c4=rand()*5/32768;
if ((c4!=0)&&(c4!=d3)&&(c4!=d4)&&(c4!=c1)&&(c4!=a4)){
break;
}}

printf("c4 = %d\n",c4);

// Central square

while((b2!=0)||(b2=a1)||(b2=b1)||(b2=a2)||(b2=d2)||(b2=b4)){
b2=rand()*5/32768;
if ((b2!=0)&&(b2!=a1)&&(b2!=b1)&&(b2!=a2)&&(b2!=d2)&&(b2!=b4)){
break;
}}

printf("b2 = %d\n",b2);

while((c2!=0)||(c2=c1)||(c2=d1)||(c2=a2)||(c2=b2)||(c2=d2)||(c2=c4)){
c2=rand()*5/32768;
if ((c2!=0)&&(c2!=c1)&&(c2!=d1)&&(c2!=a2)&&(c2!=b2)&&(c2!=d2)&&(c2!=c4)){
break;
}}

printf("c2 = %d\n",c2);

while((b3!=0)||(b3=a3)||(b3=a4)||(b3=b4)||(b3=b1)||(b3=b2||(b3=d3))){
b3=rand()*5/32768;
if ((b3!=0)&&(b3!=a3)&&(b3!=a4)&&(b3!=b4)&&(b3!=b1)&&(b3!=b2)&&(b3!=d3)){
break;
}}

printf("b3 = %d\n",b3);

while((c3!=0)||(c3=c4)||(c3=d4)||(c3=d3)||(c3=c1)||(c3=c2)||(c3=a3)||(c3=b3)){
c3=rand()*5/32768;
if ((c3!=0)&&(c3!=c4)&&(c3!=d4)&&(c3!=d3)&&(c3!=c1)&&(c3!=c2)&&(c3!=a3)&&(c3!=b3)){
break;
printf("c3 = %d\n",c3);

}}}

In that code the program works but sometimes it reach a absurd situation and the program stops for example, at the ninth variable:
2 1 3 4
4 ? ? 1
1 ? ? 2
3 ? ? !
To solve this issue I've tried to put all the process into another while-if-break senetence in order to finish the program only when the last variable to be determinated (c3) has a valor.
I've wrote that:

Code:

//sudoku.cpp:

#include<stdlib.h>
#include<math.h>
#include<stdio.h>
#include<time.h>

void main(){

srand(time(0));

	int a1;
	int b1;
	int c1;
	int d1;
	int a2;
	int b2;
	int c2;
	int d2;
        int a3;
	int b3;
	int c3;
	int d3;
        int a4;
	int b4;
	int c4;
	int d4;

srand(time(0));


d4=0;
while(d4=0){

// 1st row

a1=(rand()%4)+1; 

printf("a1 = %d\n",a1);

while((b1!=0)||(b1=a1)){
b1=rand()*5/32768;
if ((b1!=0)&&(b1!=a1)){ 
break;
printf("b1 %d\n",b1);
}}

printf("b1 = %d\n",b1);

while((c1!=0)||(c1=a1)||(c1=b1)){
c1=rand()*5/32768;
if ((c1!=0)&&(c1!=a1)&&(c1!=b1)){
break;
}}
printf("c1 = %d\n",c1);

while((d1!=0)||(d1=a1)||(d1=b1)||(d1=c1)){
d1=rand()*5/32768;
if ((d1!=0)&&(d1!=a1)&&(d1!=b1)&&(d1!=c1)){
break;
}}
printf("d1 = %d\n",d1);


// Column A

while((a2!=0)||(a2=a1)||(a2=b1)){
a2=rand()*5/32768;
if ((a2!=0)&&(a2!=a1)&&(a2!=b1)){
break;
}}

printf("a2 = %d\n",a2);

while((a3!=0)||(a3=a1)||(a3=a2)){
a3=rand()*5/32768;
if ((a3!=0)&&(a3!=a1)&&(a3!=a2)){
break;
}}

printf("a3 = %d\n",a3);


while((a4!=0)||(a4=a1)||(a4=a2)||(a4=a3)){
a4=rand()*5/32768;
if ((a4!=0)&&(a4!=a1)&&(a4!=a2)&&(a4!=a3)){
break;
}}

printf("a4 = %d\n",a4);

// Column D

while((d2!=0)||(d2=c1)||(d2=d1)||(d2=a2)){
d2=rand()*5/32768;
if ((d2!=0)&&(d2!=c1)&&(d2!=d1)&&(d2!=a2)){
break;
}}

printf("d2 = %d\n",d2);


while((d3!=0)||(d3=d1)||(d3=d2)||(d3=a3)){
d3=rand()*5/32768;
if ((d3!=0)&&(d3!=d1)&&(d3!=d2)&&(d3!=a3)){
break;
}}

printf("d3 = %d\n",d3);


while((d4!=0)||(d4=d1)||(d4=d2)||(d4=d3)||(d4=a4)){
d4=rand()*5/32768;
if ((d4!=0)&&(d4!=d1)&&(d4!=d2)&&(d4!=d3)&&(d4!=a4)){
break;
}}

printf("d4 = %d\n",d4);

// 4th row

while((b4!=0)||(b4=a3)||(b4=a4)||(b4=b1)||(b4=d4)){
b4=rand()*5/32768;
if ((b4!=0)&&(b4!=a3)&&(b4!=a4)&&(b4!=b1)&&(b4!=d4)){
break;
}}

printf("b4 = %d\n",b4);

while((c4!=0)||(c4=d3)||(c4=d4)||(c4=c1)||(c4=a4)||(c4=b4)){
c4=rand()*5/32768;
if ((c4!=0)&&(c4!=d3)&&(c4!=d4)&&(c4!=c1)&&(c4!=a4)){
break;
}}

printf("c4 = %d\n",c4);

// Central square 

while((b2!=0)||(b2=a1)||(b2=b1)||(b2=a2)||(b2=d2)||(b2=b4)){
b2=rand()*5/32768;
if ((b2!=0)&&(b2!=a1)&&(b2!=b1)&&(b2!=a2)&&(b2!=d2)&&(b2!=b4)){
break;
}}

printf("b2 = %d\n",b2);

while((c2!=0)||(c2=c1)||(c2=d1)||(c2=a2)||(c2=b2)||(c2=d2)||(c2=c4)){
c2=rand()*5/32768;
if ((c2!=0)&&(c2!=c1)&&(c2!=d1)&&(c2!=a2)&&(c2!=b2)&&(c2!=d2)&&(c2!=c4)){
break;
}}

printf("c2 = %d\n",c2);

while((b3!=0)||(b3=a3)||(b3=a4)||(b3=b4)||(b3=b1)||(b3=b2||(b3=d3))){
b3=rand()*5/32768;
if ((b3!=0)&&(b3!=a3)&&(b3!=a4)&&(b3!=b4)&&(b3!=b1)&&(b3!=b2)&&(b3!=d3)){
break;
}}

printf("b3 = %d\n",b3);

while((c3!=0)||(c3=c4)||(c3=d4)||(c3=d3)||(c3=c1)||(c3=c2)||(c3=a3)||(c3=b3)){
c3=rand()*5/32768;
if ((c3!=0)&&(c3!=c4)&&(c3!=d4)&&(c3!=d3)&&(c3!=c1)&&(c3!=c2)&&(c3!=a3)&&(c3!=b3)){
break;
}}

printf("c3 = %d\n",c3);

if (b4!=0){ 
break;
}}

printf("a1 = %d\n",a1);

}

In that code original printf sentences doesn't appears when I run the program and the last one appera like no initialized.
How can I solve that problem?
Thank you for your help.

1. main returns an int
http://faq.cprogramming.com/cgi-bin/...&id=1043284376

2. Learn how to indent code. Not only will it make it much easier for you to follow, when you come to ask for help, people will be more inclined to help you.
So rather than this

Code:

while((a2!=0)||(a2=a1)||(a2=b1)){
a2=rand()*5/32768;
if ((a2!=0)&&(a2!=a1)&&(a2!=b1)){
break;
}}

Have this

Code:

while((a2!=0)||(a2=a1)||(a2=b1)){
    a2=rand()*5/32768;
    if ((a2!=0)&&(a2!=a1)&&(a2!=b1)){
        break;
    }
}

3. Read up on arrays, in particular consider
int puzzle[4][4];
in place of 16 named variables.
You'll then be able to use for loops to sum rows and columns rather than endlessly copy/pasting code and substituting variables.

Thank you for your answer, Salem. I'll try to solve the problem and follow your advices and I'll write my results.

Hi, I've looked out of the issue "main returns an int" and I've came to the conclusion that I should use "int main ( int argc, char *argv[] )" model. Although I've tried to apply this in my source code and it has generated a large number of errors. How can I specifically implement that in my code. Have I got to put any more specific sentences? Thank you a lot.

You can specifically implement that by typing int main() instead of void main().

What are the error messages?

It's hard to help you if you neither post your latest code or your actual error messages. "I got some errors" doesn't tell us much.

Hi, I was thinking I should use "( int argc, char *argv[] )" model as in http://faq.cprogramming.com/cgi-bin/...&id=1043284376
I've read "int main ( void )" model is used when you do not require access to the command line arguments bearing in mind that, later, I want to remove some valors that should be entered by an user so I want to make a game. I am right with "( int argc, char *argv[] )" model? Anyway I've tried to use the other one too and I haven't got errors but in that code original printf sentences between while-if-break senetences don't appear when I run the program and the last one appers like no initialized so I don't solve the problem yet. (I've get that warning: warning C4508: 'main' : function should return a value; 'void' return type assumed). Here there is this last code (I've just typed int main() instead of void main()).

Code:

   
//sudoku.cpp:

#include<stdlib.h>
#include<math.h>
#include<stdio.h>
#include<time.h>

int main(){

srand(time(0));

	int a1;
	int b1;
	int c1;
	int d1;
	int a2;
	int b2;
	int c2;
	int d2;
        int a3;
	int b3;
	int c3;
	int d3;
        int a4;
	int b4;
	int c4;
	int d4;

srand(time(0));


d4=0;
while(d4=0){

// 1st row

a1=(rand()%4)+1; 

printf("a1 = %d\n",a1);

while((b1!=0)||(b1=a1)){
b1=rand()*5/32768;
if ((b1!=0)&&(b1!=a1)){ 
break;
printf("b1 %d\n",b1);
}}

printf("b1 = %d\n",b1);

while((c1!=0)||(c1=a1)||(c1=b1)){
c1=rand()*5/32768;
if ((c1!=0)&&(c1!=a1)&&(c1!=b1)){
break;
}}
printf("c1 = %d\n",c1);

while((d1!=0)||(d1=a1)||(d1=b1)||(d1=c1)){
d1=rand()*5/32768;
if ((d1!=0)&&(d1!=a1)&&(d1!=b1)&&(d1!=c1)){
break;
}}
printf("d1 = %d\n",d1);


// Column A

while((a2!=0)||(a2=a1)||(a2=b1)){
a2=rand()*5/32768;
if ((a2!=0)&&(a2!=a1)&&(a2!=b1)){
break;
}}

printf("a2 = %d\n",a2);

while((a3!=0)||(a3=a1)||(a3=a2)){
a3=rand()*5/32768;
if ((a3!=0)&&(a3!=a1)&&(a3!=a2)){
break;
}}

printf("a3 = %d\n",a3);


while((a4!=0)||(a4=a1)||(a4=a2)||(a4=a3)){
a4=rand()*5/32768;
if ((a4!=0)&&(a4!=a1)&&(a4!=a2)&&(a4!=a3)){
break;
}}

printf("a4 = %d\n",a4);

// Column D

while((d2!=0)||(d2=c1)||(d2=d1)||(d2=a2)){
d2=rand()*5/32768;
if ((d2!=0)&&(d2!=c1)&&(d2!=d1)&&(d2!=a2)){
break;
}}

printf("d2 = %d\n",d2);


while((d3!=0)||(d3=d1)||(d3=d2)||(d3=a3)){
d3=rand()*5/32768;
if ((d3!=0)&&(d3!=d1)&&(d3!=d2)&&(d3!=a3)){
break;
}}

printf("d3 = %d\n",d3);


while((d4!=0)||(d4=d1)||(d4=d2)||(d4=d3)||(d4=a4)){
d4=rand()*5/32768;
if ((d4!=0)&&(d4!=d1)&&(d4!=d2)&&(d4!=d3)&&(d4!=a4)){
break;
}}

printf("d4 = %d\n",d4);

// 4th row

while((b4!=0)||(b4=a3)||(b4=a4)||(b4=b1)||(b4=d4)){
b4=rand()*5/32768;
if ((b4!=0)&&(b4!=a3)&&(b4!=a4)&&(b4!=b1)&&(b4!=d4)){
break;
}}

printf("b4 = %d\n",b4);

while((c4!=0)||(c4=d3)||(c4=d4)||(c4=c1)||(c4=a4)||(c4=b4)){
c4=rand()*5/32768;
if ((c4!=0)&&(c4!=d3)&&(c4!=d4)&&(c4!=c1)&&(c4!=a4)){
break;
}}

printf("c4 = %d\n",c4);

// Central square

while((b2!=0)||(b2=a1)||(b2=b1)||(b2=a2)||(b2=d2)||(b2=b4)){
b2=rand()*5/32768;
if ((b2!=0)&&(b2!=a1)&&(b2!=b1)&&(b2!=a2)&&(b2!=d2)&&(b2!=b4)){
break;
}}

printf("b2 = %d\n",b2);

while((c2!=0)||(c2=c1)||(c2=d1)||(c2=a2)||(c2=b2)||(c2=d2)||(c2=c4)){
c2=rand()*5/32768;
if ((c2!=0)&&(c2!=c1)&&(c2!=d1)&&(c2!=a2)&&(c2!=b2)&&(c2!=d2)&&(c2!=c4)){
break;
}}

printf("c2 = %d\n",c2);

while((b3!=0)||(b3=a3)||(b3=a4)||(b3=b4)||(b3=b1)||(b3=b2||(b3=d3))){
b3=rand()*5/32768;
if ((b3!=0)&&(b3!=a3)&&(b3!=a4)&&(b3!=b4)&&(b3!=b1)&&(b3!=b2)&&(b3!=d3)){
break;
}}

printf("b3 = %d\n",b3);

while((c3!=0)||(c3=c4)||(c3=d4)||(c3=d3)||(c3=c1)||(c3=c2)||(c3=a3)||(c3=b3)){
c3=rand()*5/32768;
if ((c3!=0)&&(c3!=c4)&&(c3!=d4)&&(c3!=d3)&&(c3!=c1)&&(c3!=c2)&&(c3!=a3)&&(c3!=b3)){
break;
}}

printf("c3 = %d\n",c3);

if (b4!=0){ 
break;
}}

printf("a1 = %d\n",a1);

}

I've tried the "( int argc, char *argv[] )" model too, I dunno if I'm in the right way anyway I've post here it:

Code:

//sudoku.cpp:

#include<stdlib.h>
#include<math.h>
#include<stdio.h>
#include<time.h>

int main(int a1, int b1, int c1, int d1, int a2, int b2, int c2, int d2, int a3, int b3, int c3, int d3, int a4, int b4, int c4, int d4){

srand(time(0));

	int a1;
	int b1;
	int c1;
	int d1;
	int a2;
	int b2;
	int c2;
	int d2;
        int a3;
	int b3;
	int c3;
	int d3;
        int a4;
	int b4;
	int c4;
	int d4;

srand(time(0));


d4=0;
while(d4=0){

// 1st row

a1=(rand()%4)+1; 

printf("a1 = %d\n",a1);

while((b1!=0)||(b1=a1)){
b1=rand()*5/32768;
if ((b1!=0)&&(b1!=a1)){ 
break;
printf("b1 %d\n",b1);
}}

printf("b1 = %d\n",b1);

while((c1!=0)||(c1=a1)||(c1=b1)){
c1=rand()*5/32768;
if ((c1!=0)&&(c1!=a1)&&(c1!=b1)){
break;
}}
printf("c1 = %d\n",c1);

while((d1!=0)||(d1=a1)||(d1=b1)||(d1=c1)){
d1=rand()*5/32768;
if ((d1!=0)&&(d1!=a1)&&(d1!=b1)&&(d1!=c1)){
break;
}}
printf("d1 = %d\n",d1);


// Column A

while((a2!=0)||(a2=a1)||(a2=b1)){
a2=rand()*5/32768;
if ((a2!=0)&&(a2!=a1)&&(a2!=b1)){
break;
}}

printf("a2 = %d\n",a2);

while((a3!=0)||(a3=a1)||(a3=a2)){
a3=rand()*5/32768;
if ((a3!=0)&&(a3!=a1)&&(a3!=a2)){
break;
}}

printf("a3 = %d\n",a3);


while((a4!=0)||(a4=a1)||(a4=a2)||(a4=a3)){
a4=rand()*5/32768;
if ((a4!=0)&&(a4!=a1)&&(a4!=a2)&&(a4!=a3)){
break;
}}

printf("a4 = %d\n",a4);

// Column D

while((d2!=0)||(d2=c1)||(d2=d1)||(d2=a2)){
d2=rand()*5/32768;
if ((d2!=0)&&(d2!=c1)&&(d2!=d1)&&(d2!=a2)){
break;
}}

printf("d2 = %d\n",d2);


while((d3!=0)||(d3=d1)||(d3=d2)||(d3=a3)){
d3=rand()*5/32768;
if ((d3!=0)&&(d3!=d1)&&(d3!=d2)&&(d3!=a3)){
break;
}}

printf("d3 = %d\n",d3);


while((d4!=0)||(d4=d1)||(d4=d2)||(d4=d3)||(d4=a4)){
d4=rand()*5/32768;
if ((d4!=0)&&(d4!=d1)&&(d4!=d2)&&(d4!=d3)&&(d4!=a4)){
break;
}}

printf("d4 = %d\n",d4);

// 4th row

while((b4!=0)||(b4=a3)||(b4=a4)||(b4=b1)||(b4=d4)){
b4=rand()*5/32768;
if ((b4!=0)&&(b4!=a3)&&(b4!=a4)&&(b4!=b1)&&(b4!=d4)){
break;
}}

printf("b4 = %d\n",b4);

while((c4!=0)||(c4=d3)||(c4=d4)||(c4=c1)||(c4=a4)||(c4=b4)){
c4=rand()*5/32768;
if ((c4!=0)&&(c4!=d3)&&(c4!=d4)&&(c4!=c1)&&(c4!=a4)){
break;
}}

printf("c4 = %d\n",c4);

// Central square

while((b2!=0)||(b2=a1)||(b2=b1)||(b2=a2)||(b2=d2)||(b2=b4)){
b2=rand()*5/32768;
if ((b2!=0)&&(b2!=a1)&&(b2!=b1)&&(b2!=a2)&&(b2!=d2)&&(b2!=b4)){
break;
}}

printf("b2 = %d\n",b2);

while((c2!=0)||(c2=c1)||(c2=d1)||(c2=a2)||(c2=b2)||(c2=d2)||(c2=c4)){
c2=rand()*5/32768;
if ((c2!=0)&&(c2!=c1)&&(c2!=d1)&&(c2!=a2)&&(c2!=b2)&&(c2!=d2)&&(c2!=c4)){
break;
}}

printf("c2 = %d\n",c2);

while((b3!=0)||(b3=a3)||(b3=a4)||(b3=b4)||(b3=b1)||(b3=b2||(b3=d3))){
b3=rand()*5/32768;
if ((b3!=0)&&(b3!=a3)&&(b3!=a4)&&(b3!=b4)&&(b3!=b1)&&(b3!=b2)&&(b3!=d3)){
break;
}}

printf("b3 = %d\n",b3);

while((c3!=0)||(c3=c4)||(c3=d4)||(c3=d3)||(c3=c1)||(c3=c2)||(c3=a3)||(c3=b3)){
c3=rand()*5/32768;
if ((c3!=0)&&(c3!=c4)&&(c3!=d4)&&(c3!=d3)&&(c3!=c1)&&(c3!=c2)&&(c3!=a3)&&(c3!=b3)){
break;
}}

printf("c3 = %d\n",c3);

if (b4!=0){ 
break;
}}

printf("a1 = %d\n",a1);

}

With this code I get these errors:
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(13) : error C2082: redefinition of formal parameter 'a1'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(14) : error C2082: redefinition of formal parameter 'b1'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(15) : error C2082: redefinition of formal parameter 'c1'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(16) : error C2082: redefinition of formal parameter 'd1'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(17) : error C2082: redefinition of formal parameter 'a2'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(18) : error C2082: redefinition of formal parameter 'b2'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(19) : error C2082: redefinition of formal parameter 'c2'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(20) : error C2082: redefinition of formal parameter 'd2'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(21) : error C2082: redefinition of formal parameter 'a3'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(22) : error C2082: redefinition of formal parameter 'b3'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(23) : error C2082: redefinition of formal parameter 'c3'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(24) : error C2082: redefinition of formal parameter 'd3'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(25) : error C2082: redefinition of formal parameter 'a4'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(26) : error C2082: redefinition of formal parameter 'b4'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(27) : error C2082: redefinition of formal parameter 'c4'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(28) : error C2082: redefinition of formal parameter 'd4'

And this warning:
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(179) : warning C4508: 'main' : function should return a value; 'void' return type assumed

If it's the correct way, how to solve these errors? If it's not how to make it work correctly (showing variables initialized)?
Thank you

I've read "int main ( void )" model is used when you do not require access to the command line arguments bearing in mind that, later, I want to remove some valors that should be entered by an user so I want to make a game. I am right with "( int argc, char *argv[] )" model?

That is true: you would use int main() or int main(void) if you didn't want command line arguments, and int main(int argc, char *argv[]) if you did want them.

Do you know what command-line arguments are? Basically, they are extra text that can be typed when you run the program from the command line. (Command-line arguments can also be specified in shortcuts.) If you just want to get some input from the user, you won't need to be using them.

I would like to help you, but you indentation stinks. Your code is barely readable. Instead of this:

Code:

while((d1!=0)||(d1=a1)||(d1=b1)||(d1=c1)){
d1=rand()*5/32768;
if ((d1!=0)&&(d1!=a1)&&(d1!=b1)&&(d1!=c1)){
break;
}}
printf("d1 = %d\n",d1);

Code:

while( (d1 != 0) || (d1 = a1) || (d1 = b1) || (d1 = c1) )
{
    d1=rand()*5/32768;
    if ( (d1 != 0) && (d1 != a1) && (d1 != b1) && (d1 != c1))
    {
           break;
    }
}
printf("d1 = %d\n",d1);

Just from that small segement you can easily see that you are doing variable assignment in a conditional. You want to use

Code:

while( (d1 != 0) || (d1 == a1) || (d1 == b1) || (d1 == c1) )
{
    d1=rand()*5/32768;
    if ( (d1 != 0) && (d1 != a1) && (d1 != b1) && (d1 != c1))
    {
           break;
    }
}
printf("d1 = %d\n",d1);

Hi,

you would use int main() or int main(void) if you didn't want command line arguments, and int main(int argc, char *argv[]) if you did want them.

Do you know what command-line arguments are? Basically, they are extra text that can be typed when you run the program from the command line. (Command-line arguments can also be specified in shortcuts.) If you just want to get some input from the user, you won't need to be using them.

I want to get some input from user but I want to compare the user's answer with values got with that code in order to determinate their validity so I think I should use int main(int argc, char *argv[]). That's right? (I dunno if it has anything to do with that but later I want to use arrays in place of 16 variables, too)
I've post the code here:

Code:

//sudoku.cpp:

#include<stdlib.h>
#include<math.h>
#include<stdio.h>
#include<time.h>

int main(int a1, int b1, int c1, int d1, int a2, int b2, int c2, int d2, int a3, int b3, int c3, int d3, int a4, int b4, int c4, int d4){

srand(time(0));

	int a1;
	int b1;
	int c1;
	int d1;
	int a2;
	int b2;
	int c2;
	int d2;
        int a3;
	int b3;
	int c3;
	int d3;
        int a4;
	int b4;
	int c4;
	int d4;

srand(time(0));


d4=0;

while(d4=0)
{



// 1st row

a1=(rand()%4)+1; 

printf("a1 = %d\n",a1);

while((b1!=0)||(b1=a1))
{
   b1=rand()*5/32768;
   if ((b1!=0)&&(b1!=a1))
   { 
      break;
   }  
}  
printf("b1 = %d\n",b1);



while((c1!=0)||(c1=a1)||(c1=b1))
{
   c1=rand()*5/32768;
   if ((c1!=0)&&(c1!=a1)&&(c1!=b1))
   {
      break;
   }
} 
printf("c1 = %d\n",c1);



while((d1!=0)||(d1=a1)||(d1=b1)||(d1=c1))
{
   d1=rand()*5/32768;
   if ((d1!=0)&&(d1!=a1)&&(d1!=b1)&&(d1!=c1))
   {
     break;
   }
}  
printf("d1 = %d\n",d1);



// Column A

while((a2!=0)||(a2=a1)||(a2=b1))
{
   a2=rand()*5/32768;
   if ((a2!=0)&&(a2!=a1)&&(a2!=b1))
   {
     break;
   }
}
printf("a2 = %d\n",a2);



while((a3!=0)||(a3=a1)||(a3=a2))
{
   a3=rand()*5/32768;
   if ((a3!=0)&&(a3!=a1)&&(a3!=a2))
   {
     break;
   }
}
printf("a3 = %d\n",a3);



while((a4!=0)||(a4=a1)||(a4=a2)||(a4=a3))
{
   a4=rand()*5/32768;
   if ((a4!=0)&&(a4!=a1)&&(a4!=a2)&&(a4!=a3))
   {
     break;
   }
}
printf("a4 = %d\n",a4);



// Column D

while((d2!=0)||(d2=c1)||(d2=d1)||(d2=a2))
{
   d2=rand()*5/32768;
   if ((d2!=0)&&(d2!=c1)&&(d2!=d1)&&(d2!=a2))
   {
     break;
   }
}
printf("d2 = %d\n",d2);



while((d3!=0)||(d3=d1)||(d3=d2)||(d3=a3))
{
   d3=rand()*5/32768;
   if ((d3!=0)&&(d3!=d1)&&(d3!=d2)&&(d3!=a3))
   {
     break;
   }
}
printf("d3 = %d\n",d3);



while((d4!=0)||(d4=d1)||(d4=d2)||(d4=d3)||(d4=a4))
{
   d4=rand()*5/32768;
   if ((d4!=0)&&(d4!=d1)&&(d4!=d2)&&(d4!=d3)&&(d4!=a4))
   {
     break;
   }
}
printf("d4 = %d\n",d4);



// 4th row

while((b4!=0)||(b4=a3)||(b4=a4)||(b4=b1)||(b4=d4))
{
   b4=rand()*5/32768;
   if ((b4!=0)&&(b4!=a3)&&(b4!=a4)&&(b4!=b1)&&(b4!=d4)){
     break;
   }
}
printf("b4 = %d\n",b4);

while((c4!=0)||(c4=d3)||(c4=d4)||(c4=c1)||(c4=a4)||(c4=b4))
{
   c4=rand()*5/32768;
   if ((c4!=0)&&(c4!=d3)&&(c4!=d4)&&(c4!=c1)&&(c4!=a4))
   {
     break;
   }
}
printf("c4 = %d\n",c4);



// Central square

while((b2!=0)||(b2=a1)||(b2=b1)||(b2=a2)||(b2=d2)||(b2=b4))
{
   b2=rand()*5/32768;
   if ((b2!=0)&&(b2!=a1)&&(b2!=b1)&&(b2!=a2)&&(b2!=d2)&&(b2!=b4)){
     break;
   }
}
printf("b2 = %d\n",b2);



while((c2!=0)||(c2=c1)||(c2=d1)||(c2=a2)||(c2=b2)||(c2=d2)||(c2=c4))
{
   c2=rand()*5/32768;
   if ((c2!=0)&&(c2!=c1)&&(c2!=d1)&&(c2!=a2)&&(c2!=b2)&&(c2!=d2)&&(c2!=c4)){
     break;
   }
}
printf("c2 = %d\n",c2);



while((b3!=0)||(b3=a3)||(b3=a4)||(b3=b4)||(b3=b1)||(b3=b2||(b3=d3)))
{
  b3=rand()*5/32768;
  if ((b3!=0)&&(b3!=a3)&&(b3!=a4)&&(b3!=b4)&&(b3!=b1)&&(b3!=b2)&&(b3!=d3)){
    break;
  }
}
printf("b3 = %d\n",b3);



while((c3!=0)||(c3=c4)||(c3=d4)||(c3=d3)||(c3=c1)||(c3=c2)||(c3=a3)||(c3=b3))
{
   c3=rand()*5/32768;
   if ((c3!=0)&&(c3!=c4)&&(c3!=d4)&&(c3!=d3)&&(c3!=c1)&&(c3!=c2)&&(c3!=a3)&&(c3!=b3)){
     break;
   }
}
printf("c3 = %d\n",c3);





if (b4!=0)
   {
     break;
   }
}  

printf("a1 = %d\n",a1);

}

With this code I get these errors:
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(13) : error C2082: redefinition of formal parameter 'a1'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(14) : error C2082: redefinition of formal parameter 'b1'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(15) : error C2082: redefinition of formal parameter 'c1'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(16) : error C2082: redefinition of formal parameter 'd1'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(17) : error C2082: redefinition of formal parameter 'a2'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(18) : error C2082: redefinition of formal parameter 'b2'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(19) : error C2082: redefinition of formal parameter 'c2'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(20) : error C2082: redefinition of formal parameter 'd2'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(21) : error C2082: redefinition of formal parameter 'a3'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(22) : error C2082: redefinition of formal parameter 'b3'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(23) : error C2082: redefinition of formal parameter 'c3'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(24) : error C2082: redefinition of formal parameter 'd3'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(25) : error C2082: redefinition of formal parameter 'a4'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(26) : error C2082: redefinition of formal parameter 'b4'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(27) : error C2082: redefinition of formal parameter 'c4'
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(28) : error C2082: redefinition of formal parameter 'd4'

And this warning:
C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(179) : warning C4508: 'main' : function should return a value; 'void' return type assumed
How to solve them?

Thank you

You are not supposed to call main with all those variables, if you wan't to use command line arguments, you simply just have to type "int main(int argc, char *argv[])".

But i don't think you need that in your program, if you just wan't to get input from the user, just call main like this: "int main()".

i don't think you need that in your program, if you just wan't to get input from the user, just call main like this: "int main()"

I've done it but printf sentences between while-if-break senetences don't appear when I run the program and the last one appers like no initialized. I get the following warning: C:\Documents and Settings\-\Mis documentos\Institut\TDR\TDR (Programació en C)\SUDOKU\Sudoku\4\4.cpp(237) : warning C4508: 'main' : function should return a value; 'void' return type assumed
How to solve that?

And to fix your warning, add "return 0;" to the end of your "main".

--
Mats

And to fix your warning, add "return 0;" to the end of your "main"

I've done it and the warning has been fixed but printf sentences between while-if-break senetences don't appear when I run the program and the last one appers like no initialized already.
How to fix this issue?
Thank you
My code:

Code:

//sudoku.cpp:

#include<stdlib.h>
#include<math.h>
#include<stdio.h>
#include<time.h>

int main(){

srand(time(0));

	int a1;
	int b1;
	int c1;
	int d1;
	int a2;
	int b2;
	int c2;
	int d2;
    int a3;
	int b3;
	int c3;
	int d3;
    int a4;
	int b4;
	int c4;
	int d4;

srand(time(0));


d4=0;

while(d4=0)
{



// 1st row

a1=(rand()%4)+1; 

printf("a1 = %d\n",a1);

while((b1!=0)||(b1=a1))
{
   b1=rand()*5/32768;
   if ((b1!=0)&&(b1!=a1))
   { 
      break;
   }  
}  
printf("b1 = %d\n",b1);



while((c1!=0)||(c1=a1)||(c1=b1))
{
   c1=rand()*5/32768;
   if ((c1!=0)&&(c1!=a1)&&(c1!=b1))
   {
      break;
   }
} 
printf("c1 = %d\n",c1);



while((d1!=0)||(d1=a1)||(d1=b1)||(d1=c1))
{
   d1=rand()*5/32768;
   if ((d1!=0)&&(d1!=a1)&&(d1!=b1)&&(d1!=c1))
   {
     break;
   }
}  
printf("d1 = %d\n",d1);



// Column A

while((a2!=0)||(a2=a1)||(a2=b1))
{
   a2=rand()*5/32768;
   if ((a2!=0)&&(a2!=a1)&&(a2!=b1))
   {
     break;
   }
}
printf("a2 = %d\n",a2);



while((a3!=0)||(a3=a1)||(a3=a2))
{
   a3=rand()*5/32768;
   if ((a3!=0)&&(a3!=a1)&&(a3!=a2))
   {
     break;
   }
}
printf("a3 = %d\n",a3);



while((a4!=0)||(a4=a1)||(a4=a2)||(a4=a3))
{
   a4=rand()*5/32768;
   if ((a4!=0)&&(a4!=a1)&&(a4!=a2)&&(a4!=a3))
   {
     break;
   }
}
printf("a4 = %d\n",a4);



// Column D

while((d2!=0)||(d2=c1)||(d2=d1)||(d2=a2))
{
   d2=rand()*5/32768;
   if ((d2!=0)&&(d2!=c1)&&(d2!=d1)&&(d2!=a2))
   {
     break;
   }
}
printf("d2 = %d\n",d2);



while((d3!=0)||(d3=d1)||(d3=d2)||(d3=a3))
{
   d3=rand()*5/32768;
   if ((d3!=0)&&(d3!=d1)&&(d3!=d2)&&(d3!=a3))
   {
     break;
   }
}
printf("d3 = %d\n",d3);



while((d4!=0)||(d4=d1)||(d4=d2)||(d4=d3)||(d4=a4))
{
   d4=rand()*5/32768;
   if ((d4!=0)&&(d4!=d1)&&(d4!=d2)&&(d4!=d3)&&(d4!=a4))
   {
     break;
   }
}
printf("d4 = %d\n",d4);



// 4th row

while((b4!=0)||(b4=a3)||(b4=a4)||(b4=b1)||(b4=d4))
{
   b4=rand()*5/32768;
   if ((b4!=0)&&(b4!=a3)&&(b4!=a4)&&(b4!=b1)&&(b4!=d4)){
     break;
   }
}
printf("b4 = %d\n",b4);

while((c4!=0)||(c4=d3)||(c4=d4)||(c4=c1)||(c4=a4)||(c4=b4))
{
   c4=rand()*5/32768;
   if ((c4!=0)&&(c4!=d3)&&(c4!=d4)&&(c4!=c1)&&(c4!=a4))
   {
     break;
   }
}
printf("c4 = %d\n",c4);



// Central square

while((b2!=0)||(b2=a1)||(b2=b1)||(b2=a2)||(b2=d2)||(b2=b4))
{
   b2=rand()*5/32768;
   if ((b2!=0)&&(b2!=a1)&&(b2!=b1)&&(b2!=a2)&&(b2!=d2)&&(b2!=b4)){
     break;
   }
}
printf("b2 = %d\n",b2);



while((c2!=0)||(c2=c1)||(c2=d1)||(c2=a2)||(c2=b2)||(c2=d2)||(c2=c4))
{
   c2=rand()*5/32768;
   if ((c2!=0)&&(c2!=c1)&&(c2!=d1)&&(c2!=a2)&&(c2!=b2)&&(c2!=d2)&&(c2!=c4)){
     break;
   }
}
printf("c2 = %d\n",c2);



while((b3!=0)||(b3=a3)||(b3=a4)||(b3=b4)||(b3=b1)||(b3=b2||(b3=d3)))
{
  b3=rand()*5/32768;
  if ((b3!=0)&&(b3!=a3)&&(b3!=a4)&&(b3!=b4)&&(b3!=b1)&&(b3!=b2)&&(b3!=d3)){
    break;
  }
}
printf("b3 = %d\n",b3);



while((c3!=0)||(c3=c4)||(c3=d4)||(c3=d3)||(c3=c1)||(c3=c2)||(c3=a3)||(c3=b3))
{
   c3=rand()*5/32768;
   if ((c3!=0)&&(c3!=c4)&&(c3!=d4)&&(c3!=d3)&&(c3!=c1)&&(c3!=c2)&&(c3!=a3)&&(c3!=b3)){
     break;
   }
}
printf("c3 = %d\n",c3);





if (b4!=0)
   {
     break;
   }
}  

printf("a1 = %d\n",a1);
return 0;
}

Code:

while (d4=0)

will not execute anything, as it changes d4 to zero, then evaluates the result (zero) to see if it should do the "while" - and since zero means "false", it doesn't perform the loop.

--
Mats