how to compare element in array

hi:

I want to compare values in the 3 element array and see if they are equal, if equal display message. The code compiled but result not expect. Can someone help

Code:

---


#include <iostream>
#include <cstdlib>
using namespace std;

int main()
{
  int a[3]={1,2,3};

  for(int i=0; i<3; i++)
  {
    if(a[i] ==a[i++])
        cout<<"equal"<<endl;
    else
      cout<<"not equal"<<endl;
  }//end loop

  system("pause");
  return 0;
 }//end main

---

RESULT: equal

thank you

The increment operator, when placed AFTER the variable, only increments AFTER the variable has been used. So, that means you are comparing a[i]==a[i] then incrementing i. I would change it to this:

Code:

---

#include <iostream>
#include <cstdlib>
using namespace std;

int main()
{
  int a[3]={1,2,3};

  for(int i=0; i<2; i++)
  {
    if(a[i] ==a[i+1])
        cout<<"equal"<<endl;
    else
      cout<<"not equal"<<endl;
  }//end loop

  system("pause");
  return 0;
 }//end main

---

Note that you should only run the loop 2 times, because you can only (with this setup) compare 0 to 1, and 1 to 2.

thanks for your help. It work. But now I want to modify it so now can compare each element to see if they are all equal.

Th code work fine but want to know way to improve it. Can you show me how to do it if possible.

Code:

---


#include <iostream>
#include <cstdlib>
using namespace std;

int main()
{
  int a[3]={3,2,2};
  int tmp;
  bool flag=false; //stop condition for the loop

  for(int i=0; i<3; i++)
  {  tmp=a[0];
    if(a[i]== tmp && a[i+1]==tmp)
        flag=true;
    else
        flag= flag;
  }//end loop

  if(flag==true)
    cout<<"equal"<<endl;
  else
    cout<<"not equal"<<endl;

  system("pause");
  return 0;
 }//end main

---

thanks

Premise: if the first element is equal to all the other elements in the array, then all the elements in the array are equal.

Code:

---

bool flag = false;
//loop through the array comparing the other elements with the first
for (int i = 1; i < 3; i++) {
        if (a[0] != a[i]) {
                flag = true;
                break;
        }
}
//now if flag is still false, all elements are equal

---

hi:

I would like to compare each row in an n by 3 array to see if each element in first row is equal to next row ie

Code:

---

2 2 2            if  not equal, show the row have the same element.
3 5 4
4 6 8

---

I have the algorithm for it but not sure am i on the right track or not. Any help will do

ALGORITHM
1 read in the rows and columns using a for loop
2 extract each row in the array
for(int row=0; row<(n/n); row++)......
...
I don't know what to do then. any idea

thanks

hi:

I would like to compare each row in an n by 3 array to see if each element in first row is equal to next row ie


code:--------------------------------------------------------------------------------
2 2 2 if not equal, show the row have the same element.
3 5 4
4 6 8
--------------------------------------------------------------------------------

I have the algorithm for it but not sure am i on the right track or not. Any help will do

ALGORITHM
1 read in the rows and columns using a for loop
2 extract each row in the array
for(int row=0; row<(n/n); row++)......
...
I don't know what to do then. any idea

thanks

try something along the lines of:

Code:

---

for(int count=0; count<n; count++)
{
    if (array[count, n]==array[count++, n])
        cout<<"Equal! :)";
    else
          cout<<"Not equal :(";
}

---

i havent tested this so someone correct me if it wouldnt work.

hello hlam .
I didnt undrestand what you want from the program .
do you want to compare just the firt row with other rows or each row with the uper ?
are the firt rows elements equal?
and also
you want to compare elements that are in same colomn or each elements with all elements that are in the downer row ?


--------------------------------------------------------------------------------

Bingo the clown
the code you wrote just compare the last elements in the rows .