题目链接: https://vjudge.net/problem/POJ-1511 题目大意: 给定节点数n,和边数m,边是单向边. 问从1节点出发到2,3,...n 这些节点路程和从从这些节点回来到节点1的路程和最小值. n,m不超过1e6 思路: 和POJ-3268是一样的,大概思路都是正向从源点求最短路,然后把图反向,再从源点求最短路,但是这道题是它的进阶版本,由于点数过多,不可以用邻接矩阵存图,这里用前向星存图,同时存下两张图,一张正向,一张反向.Dijkstra算法用队列优化,注意用l…

题目链接:http://poj.org/problem?id=1511 题目大意:给你n个点,m条边(1<=n<=m<=1e6),每条边长度不超过1e9.问你从起点到各个点以及从各个点到起点的最小路程总和. 解题思路:这里用了优先队列优化的dijkstra复杂度mlogn,从起点到个点最短路径直接算就好了,算各个点到起点的最短路径,只要把边的方向反一下,再算一次从起点到个点最短路径就好了. Dijkstra: #include<iostream> #include<cs…

题目链接:http://poj.org/problem?id=1511 就是求从起点到其他点的最短距离加上其他点到起点的最短距离的和 , 注意路是单向的. 因为点和边很多, 所以用dijkstra优先队列的做法. 起点到其他点的最短距离之和就是dij一下 . 要求其他点到起点的最短距离的话就是把原先边的方向反向一下,然后再求起点到其他点的最短距离之和 , 同样dij一下. 代码如下: #include <iostream> #include <cstdio> #include &l…

题目链接:http://poj.org/problem?id=1511 题意:给出n个点和n条有向边,求所有点到源点1的来回最短路之和(保证每个点都可以往返源点1) 题目比较简单就是边和点的个数有点多所以可以用dijstra+优先队列这样复杂度就可以到v*logn #include <iostream> #include <cstring> #include <string> #include <vector> #include <queue>…

POJ 1511 Invitation Cards / UVA 721 Invitation Cards / SPOJ Invitation / UVAlive Invitation Cards / SCU 1132 Invitation Cards / ZOJ 2008 Invitation Cards / HDU 1535 (图论,最短路径) Description In the age of television, not many people attend theater perfor…

Invitation Cards Time Limit: 8000MS   Memory Limit: 262144K Total Submissions: 16178   Accepted: 5262 Description In the age of television, not many people attend theater performances. Antique Comedians of Malidinesia are aware of this fact. They wan…

题目传送门 1 2 题意:有向图,所有点先走到x点,在从x点返回,问其中最大的某点最短路程 分析:对图正反都跑一次最短路,开两个数组记录x到其余点的距离,这样就能求出来的最短路以及回去的最短路. POJ 3268 //#include <bits/stdc++.h> #include <cstdio> #include <queue> #include <algorithm> #include <cstring> using namespace…

Invitation Cards Time Limit: 8000MS   Memory Limit: 262144K Total Submissions: 27200   Accepted: 9022 Description In the age of television, not many people attend theater performances. Antique Comedians of Malidinesia are aware of this fact. They wan…

Invitation Cards Time Limit: 8000MS   Memory Limit: 262144K Total Submissions: 18198   Accepted: 5969 Description In the age of television, not many people attend theater performances. Antique Comedians of Malidinesia are aware of this fact. They wan…

In the age of television, not many people attend theater performances. Antique Comedians of Malidinesia are aware of this fact. They want to propagate theater and, most of all, Antique Comedies. They have printed invitation cards with all the necessa…