【codeforces 508A】Pasha and Pixels

【题目链接】:http://codeforces.com/contest/508/problem/A

【题意】

让你在一个n*m的方格上给方格染色;
顺序给出染色的k个格子
如果在某一时刻
有一个2*2长方形;
输出是第几个格子;

【题解】

在染色的时候;
判断一下这是4个方格中的哪一个
左上角or右上角or左下角or右下角
然后看看另外3个格子有没有被染色;
有的话就结束;

【Number Of WA】

0

【完整代码】

#include <bits/stdc++.h>
using namespace std;
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define LL long long
#define rep1(i,a,b) for (int i = a;i <= b;i++)
#define rep2(i,a,b) for (int i = a;i >= b;i--)
#define mp make_pair
#define ps push_back
#define fi first
#define se second
#define rei(x) cin >> x
#define pri(x) cout << x
#define ms(x,y) memset(x,y,sizeof x)

typedef pair<int,int> pii;
typedef pair<LL,LL> pll;

const int dx[9] = {0,1,0,-1,0,-1,-1,1,1};
const int dy[9] = {0,0,-1,0,1,-1,1,-1,1};
const double pi = acos(-1.0);
const int N = 1e3+100;

int n,m,k;
bool bo[N][N];

int main()
{
    //freopen("D:\\rush.txt","r",stdin);
    ios::sync_with_stdio(false);
    rei(n),rei(m),rei(k);
    ms(bo,false);
    rep1(i,1,k)
    {
        int x,y;
        rei(x),rei(y);
        bo[x][y] = true;
        //����
        if (bo[x+1][y]&&bo[x+1][y+1]&&bo[x][y+1]) return cout << i<<endl,0;
        //����
        if (bo[x-1][y]&&bo[x-1][y+1]&&bo[x][y+1]) return cout <<i<<endl,0;
        //����
        if (bo[x][y-1]&&bo[x-1][y-1]&&bo[x-1][y]) return cout <<i<<endl,0;
        //����
        if (bo[x][y-1]&&bo[x+1][y-1]&&bo[x+1][y]) return cout <<i<<endl,0;
    }
    cout << 0 <<endl;
    //printf("\n%.2lf sec \n", (double)clock() / CLOCKS_PER_SEC);
    return 0;
}