TAT 第一场codeforces B. Array Walk #暴力 #贪心 题目链接 题意 有\(a1, a2, ..., an\) 个格子(每个格子有各自分数),最初为1号格(初始分数为\(a1\)),支持两种走法(经过的格子分数会相应累加),只能走\(k\)步:①向右走.②向左走,但是每一次向左操作走完一格后不能再连续地向左移动,允许向左走的操作次数为\(z\).现要求你走完k次后获得的最大分数. 分析 参考了官方题解,假定我们有\(t\)次移动是向左的,那么剩下\(k-t\)次向右,我…

A.LCM Problem 题意:最小公倍数LCM(x,y),处于[l,r]之间,并且x,y也处于[l,r]之间,给出l,r找出x,y; 思路:里面最小的最小公倍数就是基于l左端点的,而那个最小公倍数就是2*l,直接判断2*l是否小于r 注意:当时看到最小公倍数,题目中提到了一个LCM(9,6)=18,就只想最大公因子.分解因式之类的问题,就想错了方向,wa的第一个是想的最大的数分解因式,结果TLE了. 1 #include<iostream> 2 #include<algorithm&…

Problem   Educational Codeforces Round 60 (Rated for Div. 2) - C. Magic Ship Time Limit: 2000 mSec Problem Description Input Output The only line should contain the minimal number of days required for the ship to reach the point (x2,y2)(x2,y2). If it…

Problem   Educational Codeforces Round 60 (Rated for Div. 2) - D. Magic Gems Time Limit: 3000 mSec Problem Description Input The input contains a single line consisting of 2 integers N and M (1≤N≤10^18, 2≤M≤100). Output Print one integer, the total n…

Educational Codeforces Round 43 (Rated for Div. 2) https://codeforces.com/contest/976 A #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define IT set<ll>::iterator #define sqr(x)…

Educational Codeforces Round 35 (Rated for Div. 2) https://codeforces.com/contest/911 A 模拟 #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define IT set<ll>::iterator #define sqr(…

Codeforces Educational Codeforces Round 44 (Rated for Div. 2) F. Isomorphic Strings 题目连接: http://codeforces.com/contest/985/problem/F Description You are given a string s of length n consisting of lowercase English letters. For two given strings s an…

Codeforces Educational Codeforces Round 44 (Rated for Div. 2) E. Pencils and Boxes 题目连接: http://codeforces.com/contest/985/problem/E Description Mishka received a gift of multicolored pencils for his birthday! Unfortunately he lives in a monochrome w…

Educational Codeforces Round 63 (Rated for Div. 2)题解 题目链接 A. Reverse a Substring 给出一个字符串,现在可以对这个字符串进行一次翻转,问是否存在一种方案,可以使得翻转后字符串的字典序可以变小.   这个很简单,贪心下就行了. 代码如下: Code #include <bits/stdc++.h> using namespace std; typedef long long ll; const int N = 3e5…

Educational Codeforces Round 39 (Rated for Div. 2) G 题意: 给一个序列\(a_i(1 <= a_i <= 10^{9}),2 <= n <= 200000\), 如果至多删除其中的一个数之后该序列为严格上升序列,那么称原序列为几乎严格上升序列. 现在每次将序列中的任意数字变成任意数字,问最少要操作几次才能将序列变成几乎严格上升子序列. 思路: 如果不考虑删除,求让整个序列都变成严格上升子序列的次数 求出\(序列a_i - i\)…