题目描述 D. Mishka and Interesting sum的意思就是给出一个数组,以及若干询问,每次询问某个区间[L, R]之间所有出现过偶数次的数字的异或和. 这个东西乍看很像是经典问题,一列数字中所有数字出现偶数次,除了一个数字只出现一次,找出那个只出现过一次的数字.然而这个问题并不是要找出现奇数次数字的异或和. 算法 有一个直观的思路是求出[L, R的异或和,再异或上[L, R]之间所有出现过的数字的异或和.这样的话就可以使得数字出现次数的奇偶性发生变化. 那么怎么求出区间[L,…

题目链接:http://codeforces.com/problemset/problem/703/A Mishka is a little polar bear. As known, little bears loves spending their free time playing dice for chocolates. Once in a wonderful sunny morning, walking around blocks of ice, Mishka met her frie…

题目链接:CF #365 (Div. 2) D - Mishka and Interesting sum 题意:给出n个数和m个询问,(1 ≤ n, m ≤ 1 000 000) ,问在每个区间里所有出现偶数次的数异或的值. 思路:容易想到,把区间内的所有的数都异或得到的是出现奇数次的数的值,然后再异或该区间内的所有出现过的数(每个数只统计一次),得到的ans了. 第一个问题:得到询问区间的所有数的异或值,由 a[1~r] ^ a[0~(l-1)] = a[l~r] 可以用数组all_xor[i…

转载自:http://www.cnblogs.com/icode-girl/p/5744409.html 题目链接:CF #365 (Div. 2) D - Mishka and Interesting sum 题意:给出n个数和m个询问,(1 ≤ n, m ≤ 1 000 000) ,问在每个区间里所有出现偶数次的数异或的值. 思路:容易想到,把区间内的所有的数都异或得到的是出现奇数次的数的值,然后再异或该区间内的所有出现过的数(每个数只统计一次),得到的ans了. 第一个问题:得到询问区间的…

题意   Mishka想要去一个国家旅行,这个国家共有个城市,城市通过道路形成一个环,即第i个城市和第个城市之间有一条道路,此外城市和之间有一条道路.这个城市中有个首中心城市,中心城市与每个城市(除了自己)之间有一条道路.第城市个城市有一个魅力值,经过一条连接第个和第个城市的道路的费用是,求所有道路的费用之和是多少?   注意:任何两个城市之间最多只有一条路. 思路   先考虑所有中心城市:每条路只能算一遍,那么我们可以得到如下公式:   其中,代表所有城市的魅力值的和,代表已经计算过的中心城市…

[链接]:CF/4892 [题意]: 一个人解决n个问题,这个问题的值比k小, 每次只能解决最左边的或者最右边的问题 解决了就消失了.问这个人能解决多少个问题. [代码]: #include<bits/stdc++.h> #define PI acos(-1.0) #define pb push_back #define F first #define S second #define debug puts #define setp cout << fixed << s…

D. Mishka and Interesting sum time limit per test 3.5 seconds memory limit per test 256 megabytes input standard input output standard output Little Mishka enjoys programming. Since her birthday has just passed, her friends decided to present her wit…

题目链接: http://codeforces.com/contest/703/problem/D D. Mishka and Interesting sum time limit per test 3.5 secondsmemory limit per test 256 megabytes 问题描述 Little Mishka enjoys programming. Since her birthday has just passed, her friends decided to prese…

F - Mishka and trip Sample Output   Hint In the first sample test: In Peter's first test, there's only one cycle with 1 vertex. First player cannot make a move and loses. In his second test, there's one cycle with 1 vertex and one with 2. No one can…

B. Mishka and trip time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output Little Mishka is a great traveller and she visited many countries. After thinking about where to travel this time, she cho…