题目链接:https://codeforces.com/contest/1373/problem/C 题意 给出一个只含有 $+$ 或 $-$ 的字符串 $s$,按如下伪代码进行操作: res = 0 for init = 0 to inf cur = init ok = true for i = 1 to |s| res = res + 1 if s[i] == '+' cur = cur + 1 else cur = cur - 1 if cur < 0 ok = false break i…

题目链接:https://codeforces.com/contest/1373/problem/D 题意 给出一个大小为 $n$ 的数组 $a$,下标为 $0 \sim n - 1$,可以进行一次反转一个区间中元素的操作,问偶数下标元素的最大和, 题解 如果反转区间长度为奇数,则下标奇偶性不同的元素间不会互换,所以反转的区间长度为偶数,反转后的区间可以看作相邻元素两两交换所得. 如:1 2 3 4 反转后为 4 3 2 1,偶数下标元素由 1 3 变成了 2 4 ,可以看作 1 与 2 相交换…

题目链接:https://codeforces.com/contest/1373/problem/B 题意 给出一个二进制串 $s$,Alica 和 Bob 每次可以选择移去 $s$ 中的一个 $10$ 或 $01$,无法选择者视为输掉游戏,判断最终谁会胜利.($1 \le t \le 1000, 1 \le |s| \le 100$) 题解一 $s$ 范围较小,$O_{(n^2)}$ 模拟. 代码 #include <bits/stdc++.h> using namespace std; v…

题目链接:https://codeforces.com/contest/1373/problem/A 题意 有两种包装的甜甜圈,第一种 $1$ 个 $a$ 元,第二种 $b$ 个 $c$ 元,问买多少个甜甜圈按第一种买会更便宜,买多少个甜甜圈按第二种买会更便宜,输出任一方案. 题解 梳理过后发现本题只需回答两个问题: 要不要买第一种包装 要不要买第二种包装 第一种包装是要买 $1$ 个,花费 $a$ 元,若买第二种替代,最少要买 $b$ 个,花费 $c$ 元,所以比较 $a$ 和 $c$ . 同…

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…