Example C Code: Sorting Using Qsort

 
#include <stdlib.h>
#include <iostream>
using namespace std;

int cmp (const void *a, const void *b) {
   if (**(long double **)a < **(long double **)b) return -1;
   if (**(long double **)a > **(long double **)b) return 1;
   return 0;
}

int main () {
   long double **A = new long double*[20];
   for (int i=0 ; i < 20 ; i++) A[i] = new long double(rand());
   for (int i=0 ; i < 20 ; i++) {
      if (i % 7 == 0) cout << "\n";
      cout << *(long double *)A[i] << " ";
   }
   cout << "\n";
   qsort(A, 20, sizeof(long double *), cmp);
   for (int i=0 ; i < 20 ; i++) {
      if (i % 7 == 0) cout << "\n";
      cout << *(long double *)A[i] << " ";
   }
   cout << "\n";
}