小数用二进制表示

#include <stdio.h>
#define STAGE_N 20
int main(){
  double num;
  printf("decimal num: ");
  scanf("%lf",&num);
  char binary[STAGE_N]={0};
  int i,j;
  double temp = num;
  
  for(i=0;i<STAGE_N;i++){
    temp = temp*2;
    if(temp >= 1) {
      binary[i] = 1;
      temp -= 1;
      if(temp < 0.000001) break;
    }
  }
  
  int n = (i<STAGE_N)?i:i-1;
  printf("0.");
  for(j=0;j<=n;j++){
    printf("%d",binary[j]);
  }
  
  return 0;
}