Number on a number

[Yannick]

I want to do a program that verifys if a number is in other number...We have a "x" between(1 and 99) and a "n" integer...
We say the number x and the n and it will verify if x is in n or not...i've tried something like this:

#include <stdio.h>

int n;
int x;
int y=0;

int main(void){

	printf("x: ");
	scanf("%d",&x);

	printf("n: ");
	scanf("%d",&n);

	verificar(x);

}

int verificar(int x){

	if (x<10)
		while (n>0){
			n=n%10;
			printf("%d",n);
			return n;
		}
}



I have a problem in the cicle cause it will print only the first number of n&10....
anyone to help?

[dwks]

To get each digit of a number one by one, consider an algorithm like this.

do {
    digit = number % 10;
    number /= 10;
} while(number);

Note that that gives you the ones column first etc. Getting the most significant digit first is a little harder, but you don't care about the order of the digits in your case as far as I can see, so that's not an issue.

Some suggestions about your code:

• Don't use global variables. You're passing x into verificar() anyway.
• Do use function prototypes, or put verificar() before main(). Prototypes would be a better approach.
• Do make sure your functions will return something no matter what. For example, if x is >= 10, verificar() doesn't return anything in a defined way.
• Do try to work out how you would do something by hand before trying to code it. You'll get better algorithms that way.

[Yannick]

thanks...

[vart]

and better do not use global vars

[dwks]

Actually, I said that in my edit. Buried deep within a list . . . .

Also consider returning 0 from the end of main().

[Yannick]

What you think of that?

#include <stdio.h>

int main(){

	int n;
	int x;
	int y=0;
	int save;

	printf("x: ");
	scanf("%d",&x);

	printf("n: ");
	scanf("%d",&n);

	if (x<10)
		do{
			y=n%10;
			n=n/10;
			if (y==x)
				save=y;

			}

		while (n);

		if (save==0)
			printf("No");
		else
			printf("Yes");


}

[mike_g]

Well the indentation could do with some work. You may also want to add some braces to go with this if statment: if (x<10). And, as said before, return 0 at the end might be a good idea to.

[Elysia]

Indentation is screwed up. I'm having trouble determining if the if save == 0 should be at function level or inside the if.

[laserlight]

You need to indent the code better:

#include <stdio.h>

int main() {
    int n;
    int x;
    int y = 0;
    int save;

    printf("x: ");
    scanf("&#37;d", &x);

    printf("n: ");
    scanf("%d", &n);

    if (x < 10)
        do {
            y = n % 10;
            n = n / 10;
            if (y == x)
                save = y;
        } while (n);

    if (save == 0)
        printf("No");
    else
        printf("Yes");

    return 0;
}

Quite clearly there is a control path where save is not properly initialised yet it is compared to 0.

[Elysia]

While this may work:

    if (x < 10)
        do {
            y = n &#37; 10;
            n = n / 10;
            if (y == x)
                save = y;
        } while (n);

It might be better to do:

if (x < 10)
{
	do {
		y = n % 10;
		n = n / 10;
		if (y == x)
			save = y;
	} while (n);
}

To avoid confusion.

[Yannick]

this guy sometimes prints 2x Yes or No...lol

[Yannick]

it was an error made by me...

[Yannick]

Now, is that he prints YesYes, or NoNo or YesNo...

#include <stdio.h>

int main(){

	int n;
	int x;
	int y=0;
	int save;

	printf("x (number between 1-99): ");
	scanf("%d",&x);
	while (x<1 || x>99){
		printf("Number not valid\n");
		printf("x (number between 1-99): ");
		scanf("%d",&x);
	}

	printf("n: ");
	scanf("%d",&n);

	if (x<10){
		do{
			y=n%10;
			n=n/10;
			if (y==x)
				save=y;
			}

		while (n);
	}

		if (save==0)
			printf("No");
		else
			printf("Yes");



/* For x>=10 */

	if (x>=10){
		do{
			y=n%100;
			n=n/100;
			if (y==x)
				save=y;
		}

		while (n);
	}

		if (save==0)
			printf("No");
		else
			printf("Yes");

	return 0;
}

[Yannick]

It was the " } "... now i think thats right...anyone has found any bug?

#include <stdio.h>

int main(){

	int n;
	int x;
	int y;
	int save;

	printf("x (number between 1-99): ");
	scanf("%d",&x);
	while (x<1 || x>99){
		printf("Number not valid\n");
		printf("x (number between 1-99): ");
		scanf("%d",&x);
	}

	printf("n: ");
	scanf("%d",&n);

	if (x<10){
		do{
			y=n%10;
			n=n/10;
			if (y==x)
				save=y;
			}

		while (n);

		if (save==0)
			printf("No");
		else
			printf("Yes");
	}





	if (x>=10){
		do{
			y=n%100;
			n=n/100;
			if (y==x)
				save=y;
		}

		while (n);

		if (save==0)
			printf("No");
		else
			printf("Yes");
	}


	return 0;
}

[Elysia]

Start indenting properly and you won't have bracket problems.
Adhere to the indentation example here http://cpwiki.sf.net/Indentation or give yourself a go at a little more in-depth tutorial here: http://cpwiki.sf.net/User:Elysia/Indentation