Monty Hall simulator in C

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

// Monty Hall problem simulator

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

  unsigned char prize_door; // Player always selects door #0 of 2
  int score_stay = 0,
    score_switch = 0;
  unsigned long i = 1, limit = argc==2? atol(argv[1]) : 100;

  srand(time(NULL));

  while(++i < limit && i > 0)
    if(prize_door = rand()%3) score_switch++;
      else score_stay++;

  printf("%d games\
    \n%d\t won by staying\
    \n%d\t won by switching\
    \n\n", i, score_stay, score_switch);

  return 0;

}