原题链接:http://codeforces.com/problemset/problem/878/A 题意:给出n个位运算操作, 化简这些操作, 使化简后的操作次数不多于5步. 思路:我们可以对二进制每一位上的1, 0, 进行讨论, 如果n次操作后1 -->1, 0 --> 1, 说明这一位要用或操作(or 1) 类似的,1 -->0, 0 -->1, 说明这一位要用异或操作(xor 1)        1 -->0, 0 -->0, 说明这一位要用与操作(and 0…

传送门 题目大意: 输入给出一串位运算,输出一个步数小于等于5的方案,正确即可,不唯一. 题目分析: 英文题的理解真的是各种误差,从头到尾都以为解是唯一的. 根据位运算的性质可以知道: 一连串的位运算最终都可以用三个位运算代替(&|^). 那么仅需对每一位的情况进行讨论,某一位: 必须变为1 (|1) 必须变为0 (&0) 必须01颠倒(^1) 最后输出3种位运算即可(输出三种最稳妥). code #include<bits/stdc++.h> using namespace…

传送门:http://codeforces.com/contest/879/problem/C 本题是一个位运算问题——位运算的等价变换. 假设位运算符“&”“|”“^”是左结合的,且优先级相同,则一个表达式:“x@a[1]@a[2]@...@a[n]”,等价于“(...((x@a[1])@a[2])...)@a[n]”.其中,“@”为位运算符“&”“|”“^”. 将表达式“x@a[1]@a[2]@...@a[n]”表示为一个简单的等价形式:“((x&a)|b)^c”,即“x&am…

You are given n strings s1, s2, ..., sn consisting of characters 0 and 1. m operations are performed, on each of them you concatenate two existing strings into a new one. On the i-th operation the concatenation saisbi is saved into a new string sn + …

C. Industrial Nim time limit per test 2 seconds memory limit per test 64 megabytes input standard input output standard output There are n stone quarries in Petrograd. Each quarry owns mi dumpers (1 ≤ i ≤ n). It is known that the first dumper of the…

Snark and Philip are preparing the problemset for the upcoming pre-qualification round for semi-quarter-finals. They have a bank of nproblems, and they want to select any non-empty subset of it as a problemset. k experienced teams are participating i…

题意 https://vjudge.net/problem/CodeForces-1230D 要组建一个小组,要求小组中每个人都不比所有人强,当一个人懂得一个算法但是另一个不懂那么前者认为他比后者强.所以这个小组要满足一个人懂得算法必定有另一个人全懂.每个人的技能是不同的,要求出这个小组能组成的技能最大值. 思路 先遍历一遍,用map记录a[i](会的算法)的个数,出现次数大于等于2的a[i],是肯定可以放到小组里的,因为有人和他的懂的相同. 然后对出现次数小于2的人,和刚才确定的人的对比,如果…

A. Short Program link http://codeforces.com/contest/878/problem/A describe Petya learned a new programming language CALPAS. A program in this language always takes one non-negative integer and returns one non-negative integer as well. In the language…

题目链接:http://codeforces.com/contest/879/problem/C C. Short Program time limit per test2 seconds memory limit per test256 megabytes Petya learned a new programming language CALPAS. A program in this language always takes one non-negative integer and re…

C. Short Program time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Petya learned a new programming language CALPAS. A program in this language always takes one non-negative integer and retur…