POJ 3249 Test for Job (拓扑排序+DP) <题目链接> 题目大意: 给定一个有向图(图不一定连通),每个点都有点权(可能为负),让你求出从源点走向汇点的路径上的最大点权和. 解题分析:想到拓扑排序就好做了,然后在拓扑的过程中进行简单的状态转移. #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <…

http://poj.org/problem?id=3249 Test for Job Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 8206   Accepted: 1831 Description Mr.Dog was fired by his company. In order to support his family, he must find a new job as soon as possible. No…

题目链接:http://poj.org/problem?id=3249 思路:dp[i]表示到点i的最大收益,初始化为-inf,然后从入度为0点开始bfs就可以了,一开始一直TLE,然后优化了好久才4000ms险过. 之后有写了个dfs记忆化搜索,果然快多了. bfs AC code: #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<q…

题目链接:http://poj.org/problem?id=3249 题意: 给你一个DAG图,问你入度为0的点到出度为0的点的最长路是多少 思路: 记忆化搜索,注意v[i]可以是负的,所以初始值要-inf. #include <iostream> #include <cstdio> #include <cstring> using namespace std; ; typedef long long LL; struct Edge { int next, to; }…

Test for Job Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 8990   Accepted: 2004 Description Mr.Dog was fired by his company. In order to support his family, he must find a new job as soon as possible. Nowadays, It's hard to have a job…

Test for Job Time Limit: 5000MS Memory Limit: 65536K Total Submissions: 13457 Accepted: 3100 Description Mr.Dog was fired by his company. In order to support his family, he must find a new job as soon as possible. Nowadays, It's hard to have a job, s…

Language: Default Test for Job Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 9733   Accepted: 2245 Description Mr.Dog was fired by his company. In order to support his family, he must find a new job as soon as possible. Nowadays, It's…

貌似是道水题.TLE了几次.把所有的输入输出改成scanf 和 printf ,有吧队列改成了数组模拟.然后就AC 了.2333333.... Description: MR.DOG 在找工作的过程中呢.遇见了这样一个问题.有n个城市,m条小道.然后要从入度为0的点出发,出度为0的点结束,中途经过的城市呢,都是要付费的.负数表示花费.正数表示收益.然后让你求收益最大或者说花费最少的总值. 貌似.BFS和DFS都会超时.不妨一试.附代码: #include<stdio.h>#include<…

思路:我们首先来一遍拓扑排序,将点按先后顺序排列于一维数组中,然后扫描一遍数组,将每个点的出边所连接的点进行更新,即可得到最优解. #include<iostream> #include<cstdio> #include<cstring> #include<queue> #include<algorithm> #define inf 2000000010 #define Maxn 100010 #define Maxm 1000010 using…

Description Mr.Dog was fired by his company. In order to support his family, he must find a new job as soon as possible. Nowadays, It's hard to have a job, since there are swelling numbers of the unemployed. So some companies often use hard tests for…