POJ 1195 mobile phones 二维树状数组
摘要:
题意很简单,就是求一定范围内子矩阵的和,数据量很大,用暴力的话一定会超时,这道题用二维的树状数组做比较简单。。。#include<stdio.h>#include<string.h>#include <iostream>using namespace std;#define MAX 1030int tree[MAX][MAX];int S,ans;int lowbit(int x){return x&(-x);}void add(int x,int y,int num){ for(int i=x;i<=S;i+=lowbit(i)) { for 阅读全文
posted @ 2011-07-23 13:09 lonelycatcher 阅读(199) 评论(0) 推荐(0) 编辑