E. Arthur and Brackets time limit per test 2 seconds memory limit per test 128 megabytes input standard input output standard output Notice that the memory limit is non-standard. Recently Arthur and Sasha have studied correct bracket sequences. Arthu…

E. Arthur and Brackets time limit per test 2 seconds memory limit per test 128 megabytes input standard input output standard output Notice that the memory limit is non-standard. Recently Arthur and Sasha have studied correct bracket sequences. Arthu…

题目链接:http://codeforces.com/contest/508/problem/E 输入一个n,表示有这么多对括号,然后有n行,每行输入一个区间,第i行的区间表示从前往后第i对括号的左括号跟右括号之间的距离在这个区间的范围内,问是否存在这样的括号序列. 我的做法是比较繁琐,稍微看了下别人的代码,比我的短,应该有更简单 的做法.我的做法是从后往前构造括号序列,每次添加一对括号之前,先把当前的括号序列扫一遍,例如这个括号序列:(())()((()))   ,很显然,现在我要新增一对括号…

题目传送门 /* 贪心 + 模拟:首先,如果蜡烛的燃烧时间小于最少需要点燃的蜡烛数一定是-1(蜡烛是1秒点一支), num[g[i]]记录每个鬼访问时已点燃的蜡烛数,若不够,tmp为还需要的蜡烛数, 然后接下来的t秒需要的蜡烛都燃烧着,超过t秒,每减少一秒灭一支蜡烛,好!!! 详细解释:http://blog.csdn.net/kalilili/article/details/43412385 */ #include <cstdio> #include <algorithm> #i…

题目传送门 /* 题意:从前面找一个数字和末尾数字调换使得变成偶数且为最大 贪心:考虑两种情况:1. 有偶数且比末尾数字大(flag标记):2. 有偶数但都比末尾数字小(x位置标记) 仿照别人写的,再看自己的代码发现有清晰的思维是多重要 */ #include <cstdio> #include <iostream> #include <algorithm> #include <cmath> #include <cstring> #include…

Codeforces Round #297 (Div. 2)D. Arthur and Walls Time Limit: 2 Sec  Memory Limit: 512 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/D Description Finally it is a day when Arthur has enough money for buying an apartment. H…

题目传送门 /* 题意:问最少替换'*'为'.',使得'.'连通的都是矩形 BFS:搜索想法很奇妙,先把'.'的入队,然后对于每个'.'八个方向寻找 在2*2的方格里,若只有一个是'*',那么它一定要被替换掉 */ #include <cstdio> #include <iostream> #include <algorithm> #include <cstring> #include <queue> using namespace std; ;…

Codeforces Round #297 (Div. 2)C. Ilya and Sticks Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/C Description In the evening, after the contest Ilya was bored, and he really felt like ma…

A. Pasha and Pixels     题意就是给一个n*m的矩阵,k次操作,一开始矩阵全白,一次操作可以染黑一个格子,问第几次操作可以使得矩阵中存在一个2*2的黑色矩阵.直接模拟即可 代码: #include<cstdio> #include<algorithm> #include<map> #include<cstring> #include<vector> #include<cmath> #include<stri…

C. Arthur and Table Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/557/problem/C Description Arthur has bought a beautiful big table into his new flat. When he came home, Arthur noticed that the new table is unstable. In t…