http://acm.hdu.edu.cn/showproblem.php? pid=1385 求最短路.要求输出字典序最小的路径. spfa:拿一个pre[]记录前驱,不同的是在松弛的时候.要考虑和当前点的dis值相等的情况,解决的办法是dfs找出两条路径中字典序较小的.pre[]去更新. 把路径当做字符串处理. 我仅仅用之前的pre去更新当前点,并没考虑到起点到当前点的整个路径,事实上这样并不能保证是字典序最小.wa了N次.于是乎搜了下题解,发现用spfa解的非常少.看到了某大牛的解法如上,…

Minimum Transport Cost Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 9109    Accepted Submission(s): 2405 Problem Description These are N cities in Spring country. Between each pair of cities…

链接:传送门 题意:有 n 个城市,从城市 i 到城市 j 需要话费 Aij ,当穿越城市 i 的时候还需要话费额外的 Bi ( 起点终点两个城市不算穿越 ),给出 n × n 大小的城市关系图,-1 代表两个城市无法连通,询问若干次,求出每次询问的两个城市间的最少花费以及打印出路线图 思路:经典最短路打印路径问题,直接使用一个二维数组 path[i][j] 记录由点 i 到点 j 最短路的最后后继点,这道题关键是当松弛操作相等时,i 到 j 的最短距离是可以由 k 进行跳转的,这时候需要判断这…

http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=1456 题意:求最短路并且输出字典序最小的答案. 思路:如果用dijkstra来做的话,会比较麻烦,这里直接用floyd会简单的多,只需要记录好后继路径即可. #include<iostream> #include<algorithm> #include<cstring> #include<cstdio> #include<sst…

Minimum Transport Cost Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 8794    Accepted Submission(s): 2311 Problem Description These are N cities in Spring country. Between each pair of cities…

Minimum Transport Cost http://acm.hdu.edu.cn/showproblem.php?pid=1385 Problem Description These are N cities in Spring country. Between each pair of cities there may be one transportation track or none. Now there is some cargo that should be delivere…

Minimum Transport Cost Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 8860    Accepted Submission(s): 2331 Problem Description These are N cities in Spring country. Between each pair of cities…

Minimum Transport CostTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 12860    Accepted Submission(s): 3633 Problem DescriptionThese are N cities in Spring country. Between each pair of cities t…

Minimum Transport Cost Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 10029    Accepted Submission(s): 2716 Problem Description These are N cities in Spring country. Between each pair of cities…

题目链接: https://vjudge.net/problem/ZOJ-1456 These are N cities in Spring country. Between each pair of cities there may be one transportation track or none. Now there is some cargo that should be delivered from one city to another. The transportation f…