Adieu l'ami. Koyomi is helping Oshino, an acquaintance of his, to take care of an open space around the abandoned Eikou Cram School building, Oshino's makeshift residence. The space is represented by a rectangular grid of n × m cells, arranged into n…

— This is not playing but duty as allies of justice, Nii-chan! — Not allies but justice itself, Onii-chan! With hands joined, go everywhere at a speed faster than our thoughts! This time, the Fire Sisters — Karen and Tsukihi — is heading for somewher…

Even if the world is full of counterfeits, I still regard it as wonderful. Pile up herbs and incense, and arise again from the flames and ashes of its predecessor — as is known to many, the phoenix does it like this. The phoenix has a rather long lif…

Rock... Paper! After Karen have found the deterministic winning (losing?) strategy for rock-paper-scissors, her brother, Koyomi, comes up with a new game as a substitute. The game works as follows. A positive integer n is decided first. Both Koyomi a…

D. Iahub and Xors   Iahub does not like background stories, so he'll tell you exactly what this problem asks you for. You are given a matrix a with n rows and n columns. Initially, all values of the matrix are zeros. Both rows and columns are 1-based…

题目链接:http://codeforces.com/problemset/problem/707/E 给你nxm的网格,有k条链,每条链上有len个节点,每个节点有一个值. 有q个操作,操作ask问你一个子矩阵的和是多少,操作switch将第i条链上的值0变原来的数or原来的数变0. 比较明显的二维数组数组暴力,注意的是ask操作不会超过2000,所以在switch操作的时候不能进行update操作,否则会超时.所以你在ask操作的时候update就会省时. 复杂度大概是2000*2000*l…

E. Garlands 题目连接: http://www.codeforces.com/contest/707/problem/E Description Like all children, Alesha loves New Year celebration. During the celebration he and his whole family dress up the fir-tree. Like all children, Alesha likes to play with gar…

A. Bus to Udayland time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The…

Clarke and puzzle 问题描述 克拉克是一名人格分裂患者.某一天,有两个克拉克(aa和bb)在玩一个方格游戏. 这个方格是一个n*mn∗m的矩阵,每个格子里有一个数c_{i, j}c​i,j​​. aa想开挂,想知道如何打败bb. 他们要玩qq次游戏,每一次做一次操作: 1. 取出当中的一个子矩阵(x_1, y_1)-(x_2, y_2)(x​1​​,y​1​​)−(x​2​​,y​2​​)玩游戏.两个人轮流行动,每一次只能从这个子矩阵中的一个方格c_{i, j}c​i,j​​中减…

题意 给一个10^5之内的字符串(小写字母)时限2s 输入n,有n个操作  (n<10^5) 当操作是1的时候,输入位置x和改变的字母 当操作是2的时候,输入区间l和r,有多少不同的字母 思路 二维树状数组 #include<iostream> #include<cstdio> #include<cstring> #include<queue> #include<map> #define lowbit(x) x&(-x) using…