POJ百练—IP地址转换

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int sign[9];
void change_to_8(int x)
{
    int index=8;
    while(x)
    {
        if(x&1)
        {
            sign[index]=1;
        }
        x>>=1;
        index--;
    }    
}
int main()
{
    int a[4];
    while(scanf("%d",&a[0])&&a[0]!=-1)
    {
        char p;
        scanf("%c%d%c%d%c%d", &p, &a[1], &p, &a[2], &p, &a[3]);
        for(int i=0;i<4;i++)
        {
            memset(sign,0,sizeof(sign));
            change_to_8(a[i]);
            for(int i=1;i<=8;i++)
                printf("%d",sign[i]);        
        }
        printf("
");
    }
    
    return 0;
}