// https://codeforces.com/contest/1265/problem/D /* 感觉像是遍历的思维构造题 有思路就很好做的 可以把该题想象成过山车或者山峰...... */ #include<iostream> #include<cstdio> using namespace std; int n; int cnt[5], last[5]; // last 是记录当前还有多少 0, 1, 2, 3 int ans[100005]; bool ok; int…

链接: https://codeforces.com/contest/1265/problem/E 题意: Creatnx has n mirrors, numbered from 1 to n. Every day, Creatnx asks exactly one mirror "Am I beautiful?". The i-th mirror will tell Creatnx that he is beautiful with probability pi100 for al…

链接: https://codeforces.com/contest/1265/problem/D 题意: An integer sequence is called beautiful if the difference between any two consecutive numbers is equal to 1. More formally, a sequence s1,s2,-,sn is beautiful if |si−si+1|=1 for all 1≤i≤n−1. Trans…

链接: https://codeforces.com/contest/1265/problem/C 题意: So the Beautiful Regional Contest (BeRC) has come to an end! n students took part in the contest. The final standings are already known: the participant in the i-th place solved pi problems. Since…

链接: https://codeforces.com/contest/1265/problem/B 题意: You are given a permutation p=[p1,p2,-,pn] of integers from 1 to n. Let's call the number m (1≤m≤n) beautiful, if there exists two indices l,r (1≤l≤r≤n), such that the numbers [pl,pl+1,-,pr] is a…

链接: https://codeforces.com/contest/1265/problem/A 题意: A string is called beautiful if no two consecutive characters are equal. For example, "ababcb", "a" and "abab" are beautiful strings, while "aaaaaa", "abaa&…

题目链接:https://codeforces.com/contest/1265/problem/E 题目大意: 有 \(n\) 个步骤,第 \(i\) 个步骤成功的概率是 \(P_i\) ,每一步只有成功了才会进入下一步,失败了会从第 \(1\) 步重新开始测.请问成功的期望步数是多少? 解题思路: 设期望步数是 \(S\) ,则有公式如下: 实现代码如下: #include <bits/stdc++.h> using namespace std; typedef long long ll;…

链接:http://codeforces.com/contest/1265 A. Beautiful String A string is called beautiful if no two consecutive characters are equal. For example, "ababcb", "a" and "abab" are beautiful strings, while "aaaaaa", "a…

题目链接:https://codeforces.com/contest/1265/problem/A 题意 给出一个由 a, b, c, ? 组成的字符串,将 ? 替换为 a, b, c 中的一个字母,问能否字符串中所有相邻字母都不同. 题解 除非一开始字符串就不合法,否则一定可以构造出合法的字符串,因为共有三个字母可选,而替换时最多需要判断前后两个位置. 代码 #include <bits/stdc++.h> using namespace std; void solve() { strin…

题目链接:https://codeforces.com/contest/1265/problem/B 题意 给出大小为 $n$ 的一个排列,问对于每个 $i(1 \le i \le n)$,原排列中是否有一个大小为 $i$ 的连续子排列. 题解 从小到大构造排列,记录当前排列中数的最小下标和最大下标,若最小下标和最大下标的间距刚好为排列的长度,则说明大小为 $i$ 的排列是连续的. 代码一 #include <bits/stdc++.h> using namespace std; void s…