题意:给你两个长度相同的字符串\(a\)和\(b\),你可以将相同位置上的\(a\)和\(b\)的字符交换,也可以将\(a\)或\(b\)中某个位置和对应的回文位置上的字符交换,这些操作是不统计的,你可以将\(a\)的某个字符替换,操作数+1,然后可以执行上文的操作,问最少操作多少次,使得\(a\)和\(b\)相等. 题解:我们只对\(a_{i},a_{n-i+1},b_{i},b_{n-i-1}\)进行判断,如果这\(4\)个数各不相同,那么就需要修改2个\(a\),如果有\(3\)个不相同,…

Codeforces Round #521 (Div. 3)  E. Thematic Contests 题目传送门 题意: 现在有n个题目,每种题目有自己的类型要举办一次考试,考试的原则是每天只有一种题目类型一种题目类型只能出现在一天每天的题目类型不能相同,而且后一天的题目数量必须正好为前一天的两倍,第一天的题目数量是任意的求怎么安排能使题目尽量多.注意:不是天数尽量多 思路: 首先我们知道一件事,题目属于哪种类型并不重要,重要的是每种类型的个数所以我们先统计出所有类型的个数,存进一个数组,而…

[比赛链接] https://codeforces.com/contest/1006 [题解] Problem A. Adjacent Replacements        [算法] 将序列中的所有偶数替换为奇数即可 时间复杂度 : O(N) [代码] #include<bits/stdc++.h> using namespace std; template <typename T> inline void chkmax(T &x,T y) { x = max(x,y);…

Equivalent Strings Problem's Link: http://codeforces.com/contest/559/problem/B Mean: 给定两个等长串s1,s2,判断是否等价. 等价的含义为: 若长度为奇数,则必须是相同串. 若长度是偶数,则将两串都均分成长度为原串一半的两个子串l1,r1和l2,r2,其中l1和l2等价且r1和r2等价,或者l1和r2等价且l2和r1等价. analyse: 直接按照题意模拟写个递归分治就行.比赛的时候总觉得这样暴力写会TLE,…

D. Equivalent Strings Time Limit: 2 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/559/problem/B Description Today on a lecture about strings Gerald learned a new definition of string equivalency. Two strings a and b of equal length are…

B. Equivalent Strings Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/559/problem/B Description Today on a lecture about strings Gerald learned a new definition of string equivalency. Two strings a and b of equal length are…

C. Remembering Strings Time Limit: 20 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/543/problem/C Description You have multiset of n strings of the same length, consisting of lowercase English letters. We will say that those strings ar…

C - Remembering Strings 思路:最关键的一点是字符的个数比串的个数多. 然后就能状压啦. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define PII pair<int, int> #define y1 skldjfskldjg #define y2 skldfjsklejg using names…

A. Diverse Strings time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output A string is called diverse if it contains consecutive (adjacent) letters of the Latin alphabet and each letter occurs exac…

http://codeforces.com/contest/1006/problem/A Mishka got an integer array aa of length nn as a birthday present (what a surprise!). Mishka doesn't like this present and wants to change it somehow. He has invented an algorithm and called it "Mishka's A…