c语言转二进制

#include <stdio.h>
#include <stdlib.h>
#include<string.h>
#include <time.h>
//#include<math.h>
//
//#include<iostream>
//using namespace std;

#include<stdio.h> 

char temp[50] = "";

void f(int n) 
{ 
    int a;
    char b[5];
    if(n) 
        f(n/2); 
    else 
        return; 
    a = n%2;
    printf("%d",a);
    sprintf(b,"%d",a);
    strcat(temp,b);
} 

int main() 
{ 
    int n; 
    while(1) 
    { 
        memset(temp,0,50);
        scanf("%d",&n); 
        if(n<0) 
            break; 
        if(n==0) 
            printf("0"); 
        f(n); 
        printf("\n"); 
        printf("temp:%s\n",temp);
    } 
    return 0; 
}