1010_1020 最短路

本文探讨了在城市中心区域规划最优道路路径的问题,特别是针对难以操控的车辆,如拖车,以确保从各个地点收集损坏车辆并将其安全地运回公司车库。通过使用Floyd算法解决最短路径问题,实现高效车辆调度。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

                                                                                         Einbahnstrasse
                     Time Limit : 2000/1000ms (Java/Other) Memory Limit : 32768/32768K (Java/Other)
                                     Total Submission(s) : 19 Accepted Submission(s) : 7
Problem Description
Einbahnstra e (German for a one-way street) is a street on which vehicles should only move in one direction. One reason for having one-way streets is to facilitate a smoother flow of traffic through crowded areas. This is useful in city centers, especially old cities like Cairo and Damascus. Careful planning guarantees that you can get to any location starting from any point. Nevertheless, drivers must carefully plan their route in order to avoid prolonging their trip due to one-way streets. Experienced drivers know that there are multiple paths to travel between any two locations. Not only that, there might be multiple roads between the same two locations. Knowing the shortest way between any two locations is a must! This is even more important when driving vehicles that are hard to maneuver (garbage trucks, towing trucks, etc.)

You just started a new job at a car-towing company. The company has a number of towing trucks parked at the company's garage. A tow-truck lifts the front or back wheels of a broken car in order to pull it straight back to the company's garage. You receive calls from various parts of the city about broken cars that need to be towed. The cars have to be towed in the same order as you receive the calls. Your job is to advise the tow-truck drivers regarding the shortest way in order to collect all broken cars back in to the company's garage. At the end of the day, you have to report to the management the total distance traveled by the trucks.

Input
Your program will be tested on one or more test cases. The first line of each test case specifies three numbers (N , C , and R ) separated by one or more spaces. The city has N locations with distinct names, including the company's garage. C is the number of broken cars. R is the number of roads in the city. Note that 0 < N < 100 , 0<=C < 1000 , and R < 10000 . The second line is made of C + 1 words, the first being the location of the company's garage, and the rest being the locations of the broken cars. A location is a word made of 10 letters or less. Letter case is significant. After the second line, there will be exactly R lines, each describing a road. A road is described using one of these three formats:


A -v -> B
A <-v - B
A <-v -> B


A and B are names of two different locations, while v is a positive integer (not exceeding 1000) denoting the length of the road. The first format specifies a one-way street from location A to B , the second specifies a one-way street from B to A , while the last specifies a two-way street between them. A , ``the arrow", and B are separated by one or more spaces. The end of the test cases is specified with a line having three zeros (for N , C , and R .)

The test case in the example below is the same as the one in the figure.


Output
For each test case, print the total distance traveled using the following format:


k . V


Where k is test case number (starting at 1,) is a space, and V is the result.

Sample Input
4 2 5 NewTroy Midvale Metrodale NewTroy <-20-> Midvale Midvale --50-> Bakerline NewTroy <-5-- Bakerline Metrodale <-30-> NewTroy Metrodale --5-> Bakerline 0 0 0

Sample Output
1. 80

Source
2008 ANARC
 
 
这道题自己没有做出来 捣鼓了两天依旧是wa 总的来说还是字符串的处理不太熟练 比如刚开始时候用substr函数截取字符串 但是后来看了看sscanf最好用 而且将字符串转换成数字可以用strtol 这里要注意的是指针声明的时候都是char型的
 
代码:
#include <cstdio>
#include <cstring>
#include <cctype>
#include <map>
#include <string>
using namespace std;
 
const int N=110,INF=1000010;
int n,m,sz;
int g[N][N];
int q[1010];
map<string,int> mp;
void floyd()
{
    for(int k=1;k<=n;k++)
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                if(g[i][j]>g[i][k]+g[k][j])
                    g[i][j]=g[i][k]+g[k][j];
}
int main()
{
    int C=0,c;
    while(scanf("%d%d%d",&n,&c,&m),n||m||c)
    {
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                g[i][j]=(i==j?0:INF);
        mp.clear(); sz=0;
        for(int i=0;i<=c;i++)
        {
            char u[15];
            scanf("%s",u);
            if(mp[u]==0) mp[u]=++sz;
            int t=mp[u];
            q[i]=t;
        }
        for(int i=0;i<m;i++)
        {
            char u[15],v[15],w[15];
            scanf("%s%s%s",u,w,v);
            if(mp[u]==0) mp[u]=++sz;
            if(mp[v]==0) mp[v]=++sz;
            int uu=mp[u], vv=mp[v], ww;
            sscanf(w+2,"%d",&ww);
            
            if(w[strlen(w)-1]=='>' && ww<g[uu][vv]) g[uu][vv]=ww;
            if(w[0]=='<' && ww<g[vv][uu]) g[vv][uu]=ww;
        }
        floyd();
        int ans=0;
        for(int i=1;i<=c;i++) ans+=g[1][q[i]]+g[q[i]][1];
        printf("%d. %d\n",++C,ans);
    }
    return 0;
}

评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值