Is It A Tree? Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 16702    Accepted Submission(s): 3761 Problem Description A tree is a well-known data structure that is either empty (null, void, n…

Is It A Tree? Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 26002   Accepted: 8879 Description A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edge…

Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not. One day Petya encountered a tre…

tree 把每条边权是1的边断开,发现每个点离他最近的点个数就是他所在的连通块大小. 开一个并查集,每次读到边权是0的边就合并.最后Ans​i​​=size[findset(i)],size表示每个并查集根的size Ans_i=size[findset(i)],sizeAns​i​​=size[findset(i)],size表示每个并查集根的sizesize. #include<cstdio> #include<cstring> #include<algorithm>…

题目链接:http://acm.swust.edu.cn/problem/856/ Time limit(ms): 1000 Memory limit(kb): 10000 Description There are N trees in a forest. At first, each tree contains only one node as its root. And each node is marked with a number. You're asked to do the fo…

D. Fix a Tree time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A tree is an undirected connected graph without cycles. Let's consider a rooted undirected tree with n vertices, numbered 1 th…

Is It A Tree? Time Limit:1000MS     Memory Limit:10000KB     64bit IO Format:%I64d & %I64u Submit Status Description A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by direct…

tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 986    Accepted Submission(s): 452题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5606 Problem Description There is a tree(the tree is a conne…

题目链接 dalao们怎么都写的线段树合并啊.. dsu跑的好慢. \(Description\) 给定一棵\(n(n\leq 10^5)\)个点的树. 定义\(Tree[L,R]\)表示为了使得\(L\sim R\)号点两两连通,最少需要选择的边的数量. 求\[\sum_{l=1}^n\sum_{r=l}^nTree[l,r]\] \(Solution\) 枚举每条边,计算它的贡献. 那么我们要判断有多少连续区间的点跨过这条边,并不好算,反过来去求在这条边的两侧分别有多少个连续区间. 那么显然…

Is It A Tree? Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 20222    Accepted Submission(s): 456 Problem Description A tree is a well-known data structure that is either empty (null, void, not…