题目链接: hdu:http://acm.hdu.edu.cn/showproblem.php?pid=5195 bc(中文):http://bestcoder.hdu.edu.cn/contests/contest_chineseproblem.php?cid=573&pid=1002 题解: 1.拓扑排序+贪心 #include<algorithm> #include<iostream> #include<cstring> #include<cstdi…

DZY Loves Topological Sorting Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others) Total Submission(s): 866    Accepted Submission(s): 250 Problem Description A topological sort or topological ordering of a directed g…

传送门 DZY Loves Topological Sorting Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 221    Accepted Submission(s): 52 Problem Description A topological sort or topological ordering of a directed…

DZY Loves Topological Sorting Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=5195 Description A topological sort or topological ordering of a directed graph is a linear ordering of its vertices such that for ev…

DZY Loves Topological Sorting Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 1250    Accepted Submission(s): 403 Problem Description A topological sort or topological ordering of a directed g…

题意: 删去K条边,使拓扑排序后序列字典序最大 分析: 因为我们要求最后的拓扑序列字典序最大,所以一定要贪心地将标号越大的点越早入队.我们定义点i的入度为di. 假设当前还能删去k条边,那么我们一定会把当前还没入队的di≤k的最大的i找出来,把它的di条入边都删掉,然后加入拓扑序列. 删除的一定是小连大的边,因为大连小的边在拓扑序列生成的时候就去掉了 #include <iostream> #include <cstdio> #include <queue> #incl…

定义: Topological Sorting is a method of arranging the vertices in a directed acyclic graph (DAG有向无环图) as a sequence, such that for every directed edge(u,v), 即u-> v, vertex u comes before v in the ordering 注意: A topological ordering is possible if and…

传送门 题意简述:给出一张DAGDAGDAG,要求删去不超过kkk条边问最后拓扑序的最大字典序是多少. 思路:贪心帮当前不超过删边上限且权值最大的点删边,用线段树维护一下每个点的入度来支持查询即可. 注意要在选点的时候更新后继的入度 代码: #include<bits/stdc++.h> #define ri register int using namespace std; inline int read(){ int ans=0; char ch=getchar(); while(!isd…

DZY Loves Sorting Time Limit: 12000/6000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 294    Accepted Submission(s): 77 Problem Description DZY has a sequence a[1..n]. It is a permutation of integers 1∼n. Now he…

DZY Loves Sorting Time Limit: 12000/6000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 753    Accepted Submission(s): 249 Problem Description DZY has a sequence a[1..n]. It is a permutation of integers 1∼n. Now h…