#include <stdio.h>
#include <stdlib.h>
 
const int mval = 500;
const int nval = 20;
 
int r[1001];
int rII[1001];
 
int coot[501];
int cootII[501];
int cootIII[501];
int cootIV[501];
 
int x=0;
int k=0;
int j=0;
int i=0;
 
int main(void){
 
for(i; i<nval; i++){
  r[i] = rand() % 501;
  coot[r[i]]++;
  printf("%i, ", r[i]);
  }
 
for(i=0;i<500;i++)
  if(coot[i]>0){
    cootII[i] = j;
    cootIII[j] = k;
    k += coot[i];
    j++;
    }
 
 
printf("\n");
 
for(i=0; i<nval; i++){
  x = cootII[r[i]];
  rII[cootIII[x]+cootIV[x]] = i;
  cootIV[x]++;
  }
 
for(i=0; i<nval; i++)
  printf("%i, ", r[rII[i]]);
 
printf("\n\n index \n");  
 
for(i=0; i<nval; i++)
  printf("%i, ", rII[i]);
 
 
return 0;    
 
}

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