题: OvO http://codeforces.com/contest/946/problem/E CF 946E 解: 记读入串为 s ,答案串为 ans,记读入串长度为 len,下标从 1 开始. 分三种情况讨论 1.数字位数为奇数,设数字位数为 len,则输出 ( len-1 ) 个 9 即可 ,最低位为 或者,其他位为 ,(即 100001,100 这些形式),记数字位数为 len,则输出 ( len-2 ) 个 9 即可 3.数字位数为偶数,而并非是第二种情况,那么进行一次 dfs…

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\(序列a_i - i\)…

2018-03-11 http://codeforces.com/contest/946/problem/D D. Timetable time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Ivan is a student at Berland State University (BSU). There are n days in…

https://zh.wikipedia.org/wiki/%E8%BC%BE%E8%BD%89%E7%9B%B8%E9%99%A4%E6%B3%95 取模也是一样的,就当多减几次. 在欧几里得最初的描述中,商和余数是通过连续的减法来计算的,即从rk−2中不断减去rk−1直到小于rk−1.一个更高效的做法是使用整数除法和模除来计算商和余数: rk ≡ rk−2 mod rk−1 在欧几里得定义的减法版本,取余运算被减法替换 while (b!=0) { if (a>b) a=a-b; else…

D. Timetable time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Ivan is a student at Berland State University (BSU). There are n days in Berland week, and each of these days Ivan might have s…

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…