[Codeforces]Round #491 (Div. 2) 总结 这次尴尬了,D题fst,E没有做出来.... 不过还好,rating只掉了30,总体来说比较不稳,下次加油 A:If at first you don't succeed- SB题,就是注意一下特判就好了,然后我一开始wa了三次... #include<bits/stdc++.h> using namespace std; int read(){ int ans=0,w=1;char c=getchar(); while(!…
[网络流]One-Way Roads 题目描述 In the country of Via, the cities are connected by roads that can be used in both directions. However, this has been the cause of many accidents since the lanes are not separated: The drivers frequently look at their smartphon…