zoukankan      html  css  js  c++  java
  • zoj 1655 Transport Goods

    Transport Goods
    Time Limit: 2 Seconds      Memory Limit: 65536 KB
    
    The HERO country is attacked by other country. The intruder is attacking the capital so other cities must send supports to the capital. There are some roads between the cities and the goods must be transported along the roads.
    
    According the length of a road and the weight of the goods, there will be some cost during transporting. The cost rate of each road is the ratio of the cost to the weight of the goods transporting on the road. It is guaranteed that the cost rate is less than 1.
    
    On the other hand, every city must wait till all the goods arrive, and then transport the arriving goods together with its own goods to the next city. One city can only transport the goods to one city.
    
    Your task is find the maximum weight of goods which can arrive at the capital.
    
    
    Input
    
    There are several cases.
    
    For each case, there are two integers N (2 <= N <= 100) and M in the first line, where N is the number of cities including the capital (the capital is marked by N, and the other cities are marked from 1 to N-1), and M is the number of roads.
    
    Then N-1 lines follow. The i-th (1 <= i <= N - 1) line contains a positive integer (<= 5000) which represents the weight of goods which the i-th city will transport to the capital.
    
    The following M lines represent M roads. There are three numbers A, B, and C in each line which represent that there is a road between city A and city B, and the cost rate of this road is C.
    
    Process to the end of the file.
    
    
    Output
    
    For each case, output in one line the maximum weight which can be transported to the capital, accurate up to 2 demical places.
    
    
    Sample Input
    
    5 6
    10
    10
    10
    10
    1 3 0
    1 4 0
    2 3 0
    2 4 0
    3 5 0
    4 5 0
    
    
    Sample Output
    
    40.00


    求最长路径
    #include <iostream>
    #include <stdio.h>
    #include <queue>
    #include <stack>
    #include <set>
    #include <vector>
    #include <math.h>
    #include <string.h>
    #include <algorithm>
    using namespace std;
    #define N 102
    int value[N];
    double map[N][N];
    int n;
    bool b[N];
    void dijskla()
    {
        memset(b,0,sizeof(b));
        b[n]=1;
        int t=n;
        int i,k;
        double Max;
        while(--t)
        {
            Max=-1.0;
            for(i=1;i<n;i++)
            if(!b[i]&&Max<map[n][i])
             {
                 Max=map[n][i];
                 k=i;
             }
             if(Max==-1.0) break;//有些点不可达
             b[k]=1;
            for(i=1;i<n;i++)
            if(!b[i]&&map[n][i]<map[n][k]*map[k][i])
             {
                map[n][i]=map[n][k]*map[k][i];
             }
        }
    }
    int main()
    {
        int m;
        int i,j;
        double r;
        while(scanf("%d %d",&n,&m)==2)
        {
            for(i=1;i<=n;i++)
             for(j=1;j<=n;j++)
              map[i][j]=0;
            for(i=1;i<n;i++)
             scanf("%d",&value[i]);
            while(m--)
            {
                scanf("%d %d %lf",&i,&j,&r);
                if(map[i][j]<1.0-r) map[i][j]=map[j][i]=1.0-r;//有重边呀、、、郁闷
            }
            dijskla();
            double ans=0;
            for(i=1;i<n;i++)
             ans+=map[n][i]*value[i];
            printf("%.2lf\n",ans);
        }
        return 0;
    }
     
  • 相关阅读:
    ADO.NET 2.调用存储过程
    Resharper上手指南
    获取HTML源码(只取文字,判断编码,过滤标签)
    .net(c#) winform文本框只能输入数字,不能其他非法字符(转)
    ADO.NET – 3.书籍管理系统详解
    GemBox.ExcelLite.dll导出到Excel
    C#4.0图解教程 第7章 类和继承
    C#读取网站HTML内容
    C#回顾 – 1.IO文件操作
    Javascript s10 (Jquery相关手册整合及功能实现)
  • 原文地址:https://www.cnblogs.com/372465774y/p/2777568.html
Copyright © 2011-2022 走看看