Tram network in Zagreb consists of a number of intersections and rails connecting some of them. In every intersection there is a switch pointing to the one of the rails going out of the intersection. When the tram enters the intersection it can leave…

题目链接:https://vjudge.net/problem/POJ-1847 思路:想从A到B使用开关少,想清楚了就是个简单的最短路,可以把不用开开关为权值0, 要开开关为权值1,就是求A到B开开关最少的次数,题目说了,每行第一个点是第 i-th点和他正好数开关开的方向连接. #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <…

#include<iostream> #include<algorithm> #include<queue> #include<cstdio> #include<cstring> using namespace std; ,INF=0x3f3f3f3f; int h[N],e[N],v[N],w[N],ne[N],idx; int dist[N]; bool st[N]; int n,beg,en,ans; void add(int a,int…

POJ 1847 Tram (最短路径) Description Tram network in Zagreb consists of a number of intersections and rails connecting some of them. In every intersection there is a switch pointing to the one of the rails going out of the intersection. When the tram ent…

POJ 1847 最短路 每个点都有初始指向,问从起点到终点最少要改变多少次点的指向 *初始指向的那条边长度为0,其他的长度为1,表示要改变一次指向,然后最短路 =========高亮!!!==========数组要开n^2的QAQ #include <iostream> #include <cstdio> #include <queue> using namespace std; #define SZ 10005//开n^2的数组!! #define INF 1e9+…

1.poj  1847  Tram   最短路 2.总结:用dijkstra做的,算出a到其它各个点要改向的次数.其它应该也可以. 题意: 有点难懂.n个结点,每个点可通向ki个相邻点,默认指向第一个相邻点,可以改变指向.求一条从A到B的路,使用最少改变路上点的指向的次数. #include<iostream> #include<cstring> #include<cmath> #include<queue> #include<algorithm>…

http://poj.org/problem?id=1847 这道题题意不太容易理解,n个车站,起点a,终点b:问从起点到终点需要转换开关的最少次数 开始的那个点不需要转换开关 数据: 3 2 1//第一个数车站总数3,第二个数起点2,第三个数终点1 2 2 3//第一个数有2个点可到达,两个点分别是2(不需要转换开关),3(需要转换开关) 2 3 1 2 1 2可转化为最短路来写,转换开关次数当做最短路径 #include<stdio.h> #include<stdlib.h>…

Tram Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 14630 Accepted: 5397 Description Tram network in Zagreb consists of a number of intersections and rails connecting some of them. In every intersection there is a switch pointing to the o…

Tram 题目链接: http://acm.hust.edu.cn/vjudge/contest/122685#problem/N Description Tram network in Zagreb consists of a number of intersections and rails connecting some of them. In every intersection there is a switch pointing to the one of the rails goi…

Tram Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 12005   Accepted: 4365 Description Tram network in Zagreb consists of a number of intersections and rails connecting some of them. In every intersection there is a switch pointing to t…