题目链接:http://poj.org/problem?id=2378 一棵树,去掉一个点剩下的每棵子树节点数不超过n/2.问有哪些这样的点,并按照顺序输出. dfs回溯即可. //#pragma comment(linker, "/STACK:102400000, 102400000") #include <algorithm> #include <iostream> #include <cstdlib> #include <cstring&…

题意: 给定一棵树,n个节点,若删除点v使得剩下的连通快最大都不超过n/2,则称这样的点满足要求.求所有这样的点,若没有这样的点,输出NONE. 思路: 只需要拿“求树的重心”的代码改一行就OK了.因为依然是在判别最大连通块的点数. //#include <bits/stdc++.h> #include <iostream> #include <cstdio> #include <cstring> #include <cmath> #includ…

[HDU5909]Tree Cutting(FWT) 题面 vjudge 题目大意: 给你一棵\(n\)个节点的树,每个节点都有一个小于\(m\)的权值 定义一棵子树的权值为所有节点的异或和,问权值为\(0..m-1\)的所有子树的个数 题解 考虑\(dp\) 设\(f[i][j]\)表示以\(i\)为根节点的子树中,异或和为\(j\)的子树的个数 很显然,每次合并就是两个\(dp\)值做\(xor\)卷积 那么直接用\(FWT\)优化就行了 #include<iostream> #inclu…

POJ 2378 Tree Cutting:题意 求删除哪些单点后产生的森林中的每一棵树的大小都小于等于原树大小的一半 #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> #include<cmath> using namespace std; ; <<; int t,n; int f[maxn]={}; int vis[maxn]={};…

Tree Cutting Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 4834   Accepted: 2958 Description After Farmer John realized that Bessie had installed a "tree-shaped" network among his N (1 <= N <= 10,000) barns at an incredible…

Curling 2.0 Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 12158   Accepted: 5125 Description On Planet MM-21, after their Olympic games this year, curling is getting popular. But the rules are somewhat different from ours. The game is…

Description 在一个给定形状的棋盘(形状可能是不规则的)上面摆放棋子,棋子没有区别.要求摆放时任意的两个棋子不能放在棋盘中的同一行或者同一列,请编程求解对于给定形状和大小的棋盘,摆放k个棋子的所有可行的摆放方案C. Input 输入含有多组测试数据. 每组数据的第一行是两个正整数,n k,用一个空格隔开,表示了将在一个n*n的矩阵内描述棋盘,以及摆放棋子的数目. n <= 8 , k <= n ,当为-1 -1时表示输入结束.随后的n行描述了棋盘的形状:每行有n个字符,其中 # 表示…

Description You are trapped in a 3D dungeon and need to find the quickest way out! The dungeon is composed of unit cubes which may or may not be filled with rock. It takes one minute to move one unit north, south, east, west, up or down. You cannot m…

Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 16202   Accepted: 4349 Description Given a M×N matrix A. Aij ∈ {0, 1} (0 ≤ i < M, 0 ≤ j < N), could you find some rows that let every cloumn contains and only contains one 1. Input There a…

链接:http://poj.org/problem?id=2386 题解 #include<cstdio> #include<stack> using namespace std; ,MAX_N=; char a[MAX_N][MAX_M]; int N,M; //现在位置 (x,y) void dfs(int x,int y){ a[x][y]='.'; //将现在所在位置替换为'.',即旱地 ;dx<=;dx++){ //循环遍历连通的8个方向:上.下.左.右.左上.左下…