sorting 2D arrays

[Kevin G]

Hi,
I have written a program that is meant to sort a small 2 dimensional array (ten groups of two numbers) in descending order, by the first number (column [0]).

It works when I use small numbers, such as 1 2, 4 10, 3 6, 9 15, 20 56, 2 1, 5 34, 18 29, 2 2, 31 1, but when I use a bit bigger number like 2 3, 65 12, 23 3, 6 98, 25 10, 65 3, 1 2, 2 1, 43 12, 63 23. it freezes.

What have I stuff up?? and then after that is fixed.

#include <stdio.h>

#define ROWS 10
#define COLUMNS 2

int improve_order (int array[ROWS][COLUMNS], int len);

int main( int argc, char **argv) {

    int array[ROWS][COLUMNS];
    int i;
    
    printf("Enter 10 pairs of integers:\n");

    for( i=0; i<ROWS; i=i+1) {
        scanf("%d %d", &array[i][0], &array[i][1]);   
    }

    int a=1;
    while(a==1) {
        a=improve_order (array, ROWS); 
   }
    printf("Sorted in desending order for first element and asending order for second element:\n");

    for(i=0; i<ROWS; i=i+1) {
        printf("%d %d\n", array[i][0], array[i][1]);
    }
    printf("\n");

    return 0;
    
}

int improve_order (int array[ROWS][COLUMNS], int len) {
    int swapped1=0;
    int temp1,temp3;
    int i=0;

    while(i<ROWS-1) {
        if( array[i][0] < array[i+1][0]) {
            temp1=array[i][0];
            array[i][0]=array[i+1][0];
            array[i+1][0]=temp1;

            temp1=array[i][1];
            array[i][1]=array[i+1][1];
            array[i+1][1]=temp1;
            swapped1=1;
        }

         /*if ( array[i][1]> array[i+1][1]) {
           temp2=array[i][1];
           array[i][0]=array[i+1][1];
           array[i+1][1]=temp2;
           swapped1=1;
       }*/

      if ( (array[i][0]== array[i+1][0]) && (array[i][1]> array[i+1][1]) ) {
           temp3= array[i][1];
           array[i+1][i]=array[i][1];
           array[i][1]=temp3;
           swapped1=1;
      }
          
           

         i=i+1;
    }

    return swapped1; 
}

[DeadPlanet]

Think about what happens in 'improve_order' when i is 9.

[Adak]

So 11 will sort out as less than 2?