In the big cities, the subway systems always look so complex to the visitors. To give you some sense, the following figure shows the map of Beijing subway. Now you are supposed to help people with your computer skills! Given the starting position of…

最短路. 记录一下到某个点,最后是哪辆车乘到的最短距离.换乘次数以及从哪个位置推过来的,可以开$map$记录一下. #include<map> #include<set> #include<ctime> #include<cmath> #include<queue> #include<string> #include<stack> #include<vector> #include<cstdio>…

PAT甲级1131. Subway Map 题意: 在大城市,地铁系统对访客总是看起来很复杂.给你一些感觉,下图显示了北京地铁的地图.现在你应该帮助人们掌握你的电脑技能!鉴于您的用户的起始位置,您的任务是找到他/她目的地的最快方式. 输入规格: 每个输入文件包含一个测试用例.对于每种情况,第一行包含正整数N(<= 100),地铁线数.然后N行跟随,第i(i = 1,...,N)行以格式描述第i条地铁线: M S [1] S [2] ... S [M] 其中M(<= 100)是停止次数,S [i…

可以转到我的CSDN查看同样的文章https://blog.csdn.net/weixin_44385565/article/details/89003683 1131 Subway Map (30 分) In the big cities, the subway systems always look so complex to the visitors. To give you some sense, the following figure shows the map of Beijing…

题目:https://pintia.cn/problem-sets/994805342720868352/problems/994805347523346432 题意: 告诉你一个地铁线路图,站点都是用四位数来编号. 现在问你从某一起点到某一终点,经过站数最少的乘车方式是什么?要输出方案. 如果站数相同要输出换乘较少的. 思路: 首先肯定是搜索没有问题了.因为要输出方案,所以bfs不太方便存答案.很容易想到用dfs 比较麻烦的是输出方案的时候,线路相同的那些站都合并在同一个线路里了.那么我们就再…

In the big cities, the subway systems always look so complex to the visitors. To give you some sense, the following figure shows the map of Beijing subway. Now you are supposed to help people with your computer skills! Given the starting position of…

In the big cities, the subway systems always look so complex to the visitors. To give you some sense, the following figure shows the map of Beijing subway. Now you are supposed to help people with your computer skills! Given the starting position of…

题意:给出起点和终点,计算求出最短路径(最短路径即所经过的站点最少的),若最短路径不唯一,则选择其中换乘次数最少的一条线路. 思路:本题虽然也是求最短路径,但是此路径是不带权值的,路径长度即所经过的边数,故可以用DFS来求解,而不是用一般的Dijkstra之类的.相信若只是求最短路径,大多数人都会做,就是从起点start开始深度遍历,遍历到终点end时,与全局变量进行比较.更新.本题的关键是,更新最优路径时需要比较“换乘次数”,如何求解它呢?我是这么思考的——首先,考虑用一个二维数组int mp…

dfs,选择最优路径并输出~ 这道题难度非常炸裂,要求完完整整自己推一遍,DFS才算过关!思路:一遍dfs,过程中要维护两个变量,minCnt 中途停靠最少的站.minTransfer需要换成的最少次数1 可以这样算出一条线路的换乘次数:在line数组里保存每两个相邻站中间的线路是几号线,从头到尾遍历最终保存的路径,preLine为前一小段线路编号,如果当前的节点和前一个节点组成的这条路的编号和preLine不同,说明有一个换乘,就将cnt+1,最后遍历完累加的cnt即是换乘的次数.2 line…

Source: PAT A1131 Subway Map (30 分) Description: In the big cities, the subway systems always look so complex to the visitors. To give you some sense, the following figure shows the map of Beijing subway. Now you are supposed to help people with your…