题面 Given two integers \(n\) and \(x\), construct an array that satisfies the following conditions: ·for any element ai in the array, \(1≤ai<2^n\); ·there is no non-empty subsegment with bitwise XOR equal to \(0\) or \(x\), ·its length \(l\) should be…
Ehab's REAL Number Theory Problem 前置知识 质数 分解质因数 无向无权图最小环<讲> Ehab's REAL Number Theory Problem/onCF 给 \(n\) 个数 \(a_i\)(\(a_i\) 的因数个数不超过 \(7\)),求最少选出多少个数,使得乘积为完全平方.无解输出 \(-1\). 数据范围:\(1\le n\le 10^5\),\(1\le a_i\le 10^6\). 没想到一场普通的 \(\texttt{CF}\) 比赛能…
C. Mike and gcd problem http://www.cnblogs.com/BBBob/p/6746721.html #include<iostream> #include<cstdio> #include<string> #include<cstring> #include<algorithm> #include<cmath> using namespace std; ; int a[maxn]; int gcd(…
/* CF798 C. Mike and gcd problem http://codeforces.com/contest/798/problem/C 数论 贪心 题意:如果一个数列的gcd值大于1,则称之为美丽数列 给出数列a,可以将a_i 和 a_(i+1)换为其差和其和 如果可以变为美丽数列,输出YES并输出最少的变换次数 否则输出NO 思路: 如果变换a b a b -> a-b a+b -> -2b 2a 因此变换两个可以把a b乘以2 而若a b都是奇数,只需变换一次 所以每次先…
题目连接:http://codeforces.com/contest/798/problem/C C. Mike and gcd problem time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Mike has a sequence A = [a1, a2, ..., an] of length n. He considers…
题目:Mike and gcd problem 题意:给一个序列a1到an ,如果gcd(a1,a2,...an)≠1,给一种操作,可以使ai和ai+1分别变为(ai+ai+1)和(ai-ai+1);问需要执行几次这个操作才能使得gcd(a1,a2,...an)>1. 分析: 1.首先,答案总是YES. 2,假设gcd(a1,a2,...an)=1,在一次对ai和ai+1的操作后新的gcd为d,则d满足:d|ai - ai + 1 and d|ai + ai + 1 d|2ai and d|2…
C. Mike and gcd problem time limit per test: 2 seconds memory limit per test: 256 megabytes input: standard input output: standard output Mike has a sequence A = [a1, a2, ..., an] of length n. He considers the sequence B = [b1, b2, ..., bn] beautiful…
Ehab and a component choosing problem 如果有多个连接件那么这几个连接件一定是一样大的, 所以我们先找到值最大的连通块这个肯定是分数的答案. dp[ i ]表示对于 i 这棵子树包含 i 这个点的连通块的最大值, 就能求出答案, 然后知道最大值之后再就能求出几个连接件. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make…
E. Ehab and a component choosing problem 题目链接:https://codeforces.com/contest/1088/problem/E 题意: 给出一个数,找出k个连通块,使得连通块里面点的和除以k最大.当选择不同数量的连通块有相同的最大值时,要求输出k最大的情况. 题解: 由于这个不等式average(x1,x2,x3...xn)<=max(x1,x2,...xn)成立(当且仅当x1=x2=...xn时,等号成立),而题目所求正好是连通块里面点和…
D. Ehab and another another xor problem 题目链接:https://codeforces.com/contest/1088/problem/D Description: This is an interactive problem! Ehab plays a game with Laggy. Ehab has 2 hidden integers (a,b)(a,b). Laggy can ask a pair of integers (c,d)(c,d) a…
C. Mike and gcd problem time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Mike has a sequence A = [a1, a2, ..., an] of length n. He considers the sequence B = [b1, b2, ..., bn] beautiful if…
E. Ehab's REAL Number Theory Problem 数论+图论 求最小环 题目大意: 给你一个n大小的数列,数列里的每一个元素满足以下要求: 数据范围是:\(1<=a_i<=10^6\) \(a_i\) 最多只有7个因数 题目要求在这个数列找到一个最短的子数列,子数列的所有的数相乘是一个完全平方数. 题解: 这个题对于 \(x^{3}\) 应该等价于 \(x\) ,其实就是可以除去 \(a_i\)中的所有的平方项,显而易见,这个并不影响答案. 因为 \(a_i\) 最多只…
Strange Towers of Hanoi Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 2677 Accepted: 1741 Description Background Charlie Darkbrown sits in another one of those boring Computer Science lessons: At the moment the teacher just explains the…
World Cup Noise Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 16374 Accepted: 8097 Description Background "KO-RE-A, KO-RE-A" shout 54.000 happy football fans after their team has reached the semifinals of the FIFA World Cup in their…
Common Subsequence Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 22698 Accepted Submission(s): 9967 Problem Description A subsequence of a given sequence is the given sequence with some el…
