اكتب برنامج بلغة C لإيجاد أكبر عدد ممكن من مجموعة الأعداد المعطاة

/*Write a program in C to find largest number possible from the set of given numbers*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int compare(const void *a, const void *b)
{
    const char **X = (const char **)a;
    const char **Y = (const char **)b;

    int chr_len = strlen(*X) + strlen(*Y) + 1;

    char XY[chr_len];
    strcpy(XY, *X);
    strcat(XY, *Y);

    char YX[chr_len];
    strcpy(YX, *Y);
    strcat(YX, *X);

    return strcmp(YX, XY);
}

int main(void)
{
    char *arr1[] = { "15", "628", "971", "9", "2143", "12" };
    int n = sizeof(arr1)/sizeof(arr1[0]);
	int i;
 //------------- print original array ------------------	
	printf("The given numbers are :  \n");
	for(i = 0; i < n; i++)
		{
			printf("%s  ", arr1[i]);
		}
	printf("\n");
//------------------------------------------------------ 	
    qsort(arr1, n, sizeof(arr1[0]), compare);
	printf("The largest possible number by the given numbers are: ");
    for (int i = 0; i < n ; i++ )
        printf("%s", arr1[i]);
    return 0;
}