#UVa：10931－Parity

利用遞迴可以邊算邊列印0、1字串。

C++(0.012)

/*******************************************************/
/* UVa 10931 Parity                                    */
/* Author: Maplewing [at] knightzone.studio            */
/* Version: 2015/01/26                                 */
/*******************************************************/
#include <iostream>
#include <cstdio>
using namespace std;

int calculateAndPrintMod2(int number){
  if( number / 2 == 0 ){
    if( number % 2 == 1 ){
      printf("1");
    }
    return number % 2;
  }

  int mod = calculateAndPrintMod2(number / 2) + (number % 2);
  printf("%d", number % 2);

  return mod;
}

int main(){
  int I;
  while( scanf("%d", &I) != EOF && I != 0 ){
    printf("The parity of ");

    int mod = calculateAndPrintMod2(I);
    printf(" is %d (mod 2).\n", mod);
  }

  return 0;
}