UVA 10167 - Birthday Cake

这道题要求我们用一条直线将蛋糕平均分成两半，要求两边的cherrie一样多，

并且不能有cherrie 在直线上，当然也不能在外边，我们直接枚举所有的直线

的系数a，b的可能情况，遇到第一种情况输出即可。

#include<cstdio>
#include<cstring>
#include<cstdlib>

typedef struct coordinate
{
    int x, y;
}C;

C co[105];
int N, M;

void cut()
{
    int left, right, result;
    for( int a = -500; a <= 500; a ++)
        for( int b = -500; b <= 500; b ++)
        {
            left = right = 0;
            for( int i = 0; i < M; i ++)
            {
                result = co[i].x * a + co[i].y * b;
                if( result > 0) left ++;
                else if( result < 0) right ++;
                else break;
                if( left == N && right == N)
                {
                    printf( "%d %d\n", a, b);
                    return;
                }
            }
        }
}

int main()
{
    while( scanf( "%d", &N), N)
    {
        N <<= 1;
        M = 0;
        for( int i = 0; i < N; i ++)
            scanf( "%d%d", &co[i].x, &co[i].y);
        for( int i = 0; i < N; i ++)
        {
            if( co[i].x >= 100 || co[i].x <= -100 || co[i].y <= -100 || co[i].y >= 100)
                continue;
            co[M ++] = co[i];
        }
        N = M >> 1;
        cut();
    }
    return 0;
}