Codeforces Round #523 (Div. 2) C-Multiplicity
C. Multiplicity time limit per test 3 seconds memo …
Codeforces Round #523 (Div. 2) B-Views Matter
B. Views Matter time limit per test 2 secon …
Codeforces Round #523 (Div. 2) A – Coins
A. Coins time limit per test 2 seconds memory limi …
树的直径（任意两点间最长路）
定义: 一棵树的直径就是这棵树上存在的最长路径。 求法: 两次dfs或bfs。第一次任意选一个点进行 …
#522 （Div. 2）—D. Barcelonian Distance
D. Barcelonian Distance time limit per test 1 seco …
#522 (Div. 2)—C. Playing Piano
C. Playing Piano time limit per test 1 second memo …
#522 (Div. 2)—B. Personalized Cup（水题）
B. Personalized Cup time limit per test 1 second m …
#522 (Div. 2）—A. Kitchen Utensils（水题）
A. Kitchen Utensils time limit per test 1 second m …
二分的边界
while(l<=r) { int mid=(l+r)/2;//min=l+(r-l)/2 防 …
D – Cyclic Nacklace （KMP求循环节）
CC always becomes very depressed at the end …