#include <stdio.h>

static const unsigned int prime = 19448089;

unsigned int permuteQPR(unsigned int x)
{
  if (x >= prime)
    return x;  // The 5 integers out of range are mapped to themselves.
  unsigned int residue = ((unsigned long long) x * x) % prime;
  return (x <= prime / 2) ? residue : prime - residue;
}

#define CALC(x) {						\
     printf("value: %u permute: %u\n",x,permuteQPR(x));	\
  }while(0) 

void main(void) {
  CALC(0);
  CALC(3721041);
  CALC(15256836);
  CALC(prime);
  CALC(0xFFFFFFFF);
}

value: 0 permute: 0
value: 3721041 permute: 1367775
value: 15256836 permute: 1367775
value: 19448089 permute: 19448089
value: 4294967295 permute: 4294967295