ACM_Plants vs. Zombies（一元一次方程）

Plants vs. Zombies

Time Limit: 2000/1000ms (Java/Others)

Problem Description:

There is a zombie on your lawn,There is a zombie on your lawn,There are many zombies on your lawn,So can you defeat them?You have many plants that can kill the zombie in a hit and your plants can kill all zombies on their straight shooting path.

Input:

The input consists of several cases.The first line are two positive integer n,m,indicating the number of plants and zombies.Then the next n lines show the line (ax+by+c==0) of plants in the form of (a,b,c),Then the last lines show the positions of zombies in the form of (xi,yi).All input data is a 32-bit integer.

Output:

Print "duang" if you can kill all zombies,else print "eat your brain".

Sample Input:

2 2
1 1 1
1 2 3
1 -2 -1 0

Sample Output:

duang
解题思路：简单判断m个坐标是否都满足n个方程ax+by+c==0中的任意一个，如果都满足，则输出"duang"，否则输出"eat your brain"，水过！
AC代码：

#include<bits/stdc++.h>
using namespace std;
const int maxn = 1e6+5;//开大一点
int n,m,num,x,y,a[maxn],b[maxn],c[maxn];
int main(){
    while(~scanf("%d%d",&n,&m)){
        for(int i=0;i<n;++i)scanf("%d%d%d",&a[i],&b[i],&c[i]);
        num=0;
        for(int j=0;j<m;++j){
            scanf("%d%d",&x,&y);
            for(int i=0;i<n;++i)
                if(a[i]*x+b[i]*y+c[i]==0){num++;break;}
        }
        if(num!=m)printf("eat your brain
");
        else printf("duang
");
    }
    return 0;
}