poj1552---枚举

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int numList[15],th=0,i,j;
    while(scanf("%d",&numList[th++])!=EOF){
        int count=0;
        if(numList[0]==-1)
            break;
        while(scanf("%d",&numList[th])!=EOF)
        {
            if(numList[th]==0)
                break;
            ++th;
        }
        for(i=0;i<th-1;i++)
        {
            for(j=i+1;j<=th-1;j++)
            {
                if((float)numList[i]/numList[j]==0.5 || (float)numList[i]/numList[j]==2.0)
                    count++;
            }
        }
        printf("%d\n",count);
        th=0;
    }
    return 0;
}

另外附一个可读性更高的

http://www.cnblogs.com/rainydays/archive/2013/04/03/2998275.html