A. Timofey and a tree time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Each New Year Timofey and his friends cut down a tree of n vertices and bring it home. After that they paint all the n…
A. Timofey and a tree 题意:给一棵树,要求判断是否存在一个点,删除这个点后,所有连通块内颜色一样.$N,C \le 10^5$ 想法:这个叫换根吧.先求出一个点合法即其儿子的子树内颜色一样,非该点子树的点颜色都一样.可以用DFS序解决. #include< cstdio > typedef long long ll; template inline void read(T&x) { x=0;bool f=0;char c=getchar(); while((c&l…
地址:http://codeforces.com/contest/764/problem/C 题目: C. Timofey and a tree time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Each New Year Timofey and his friends cut down a tree of n vertices…
time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output Each New Year Timofey and his friends cut down a tree of n vertices and bring it home. After that they paint all the n its vertices, so that the…
Each New Year Timofey and his friends cut down a tree of n vertices and bring it home. After that they paint all the n its vertices, so that the i-th vertex gets color ci. Now it's time for Timofey birthday, and his mother asked him to remove the tre…
标题写的树形DP是瞎扯的. 先把1看作根. 预处理出f[i]表示以i为根的子树是什么颜色,如果是杂色的话,就是0. 然后从根节点开始转移,转移到某个子节点时,如果其子节点都是纯色,并且它上面的那一坨结点也是纯色,就输出解. 否则如果其上面的一坨是纯色,并且其子节点有且只有一个杂色的时候,就递归处理该子节点. #include<cstdio> #include<cstdlib> using namespace std; #define N 100050 int v[N<<…
package codeforces; import java.util.*; public class CodeForces_764C_Timofey_and_a_tree { static final int N=(int) (2e5+10); @SuppressWarnings("unchecked") static ArrayList<Integer> a[]=new ArrayList[N]; static int book[]=new int[N]; stati…
