原题链接:K-Link-Cut Tree_第46屆ICPC 東亞洲區域賽(澳門)(正式賽) (nowcoder.com) 题意: 要求一个边权值总和最小的环,并从小到大输出边权值(2的次幂):若不存在环,输出-1. 思路: 考虑按权值从小到大加边,当出现环时(利用并查集判环),这个环必定是总权值最小的环. 找到环后,不再加边,并从环上某一点做DFS,找到从该点出发并再次回到该点的环. 代码: #include <bits/stdc++.h> #define PII pair<int,in…

Range Search (kD Tree) The range search problem consists of a set of attributed records S to determine which records from Sintersect with a given range. For n points on a plane, report a set of points which are within in a given range. Note that you…

/* * tree[x].left 表示以 x 为节点的左儿子 * tree[x].right 表示以 x 为节点的右儿子 * tree[x].size 表示以 x 为根的节点的个数(大小) */ struct SBT { int key,left,right,size; } tree[10010]; int root = 0,top = 0; void left_rot(int &x) // 左旋 { int y = tree[x].right; if (!y) return; tree[x]…

题目 Source http://acm.hdu.edu.cn/showproblem.php?pid=3333 Description After inventing Turing Tree, 3xian always felt boring when solving problems about intervals, because Turing Tree could easily have the solution. As well, wily 3xian made lots of new…

这篇随笔是对Wikipedia上k-d tree词条的摘录, 我认为解释得相当生动详细, 是一篇不可多得的好文. Overview A \(k\)-d tree (short for \(k\)-dimensional tree) is a binary space-partitioning tree for organizing points in a \(k\)-dimensional space. \(k\)-d trees are a useful data structure for…

                                                          Apple Tree Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 27470   Accepted: 8140 Description There is an apple tree outside of kaka's house. Every autumn, a lot of apples will gr…

一棵树,边长都是1,问这棵树有多少点对的距离刚好为k 令tree(i)表示以i为根的子树 dp[i][j][1]:在tree(i)中,经过节点i,长度为j,其中一个端点为i的路径的个数dp[i][j][0]:在tree(i)中,经过节点i,长度为j,端点不在i的路径的个数 则目标:∑(dp[i][k][0]+dp[i][k][1])初始化:dp[i][0][1]=1,其余为0 siz[i]:tree(i)中,i与离i最远的点的距离递推:dp[i][j][0]+=dp[i][j-l][1]*dp[…

#include<iostream> #include<cstdio> #include<algorithm> #define Max 1005 using namespace std; struct line{ double x, y1, y2; int flag; }x_line[Max]; struct node{ int l, r, flag; double x, f; }tree[Max]; double point[Max]; int n, m, xm; i…

首先是从二叉搜索树开始,一棵二叉搜索树的定义是: 1.这是一棵二叉树: 2.令x为二叉树中某个结点上表示的值,那么其左子树上所有结点的值都要不大于x,其右子树上所有结点的值都要不小于x. 由二叉搜索树的第二条定义,可以很方便地利用这种特点在二叉树中以O(logn)的渐进复杂度完成插入.查找.删除等操作. 但是这里还是有个问题,就是弄不好的话,一棵普通的二叉搜索树经过多次修改操作之后可能会导致整棵树左右“不平衡”,出现一边结点很多,另一边结点很少的情况,这样最终每一次的操作时间就会大大偏离O(lo…

Dylans loves tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 1444    Accepted Submission(s): 329 Problem Description Dylans is given a tree with N nodes. All nodes have a value A[i].Nodes…