UVA 11121 - Base -2 (十進制數轉化爲-2進制)

算法：

int n,c = -1;
a[0] = 0;
while(n)
{
    a[++c] = n%base; //base<0爲負進制
    n/=base;
    if(a[c]<0)
    {
        a[c]+=base;
        n++;
    }
}
while(c>0)
    printf("%d",a[c--]);
printf("%d\n",a[0]);

#include<cstdio>
#include<iostream>
#include<cstring>
#include<cmath>

using namespace std;

int a[110];

int main()
{
    int n,T,cas = 1;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d",&n);
        int c = -1;
        a[0] = 0;
        while(n)
        {
            a[++c] = n%(-2);
            n/=(-2);
            if(a[c]<0)
            {
                a[c] += 2;
                n++;
            }
        }
        printf("Case #%d: ",cas++);
        while(c>0)
            printf("%d",a[c--]);
        printf("%d\n",a[0]);
    }
    return 0;
}