Bus System

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 7834    Accepted Submission(s): 2042

Problem Description

Because of the huge population of China, public transportation is very important. Bus is an important transportation method in traditional public transportation system. And it’s still playing an important role even now.
The bus system of City X is quite strange. Unlike other city’s system, the cost of ticket is calculated based on the distance between the two stations. Here is a list which describes the relationship between the distance and the cost.



Your neighbor is a person who is a really miser. He asked you to help him to calculate the minimum cost between the two stations he listed. Can you solve this problem for him?
To simplify this problem, you can assume that all the stations are located on a straight line. We use x-coordinates to describe the stations’ positions.

 

Input

The input consists of several test cases. There is a single number above all, the number of cases. There are no more than 20 cases.
Each case contains eight integers on the first line, which are L1, L2, L3, L4, C1, C2, C3, C4, each number is non-negative and not larger than 1,000,000,000. You can also assume that L1<=L2<=L3<=L4.
Two integers, n and m, are given next, representing the number of the stations and questions. Each of the next n lines contains one integer, representing the x-coordinate of the ith station. Each of the next m lines contains two integers, representing the start point and the destination.
In all of the questions, the start point will be different from the destination.
For each case,2<=N<=100,0<=M<=500, each x-coordinate is between -1,000,000,000 and 1,000,000,000, and no two x-coordinates will have the same value.

 

Output

For each question, if the two stations are attainable, print the minimum cost between them. Otherwise, print “Station X and station Y are not attainable.” Use the format in the sample.

 

Sample Input

21 2 3 4 1 3 5 74 212341 44 11 2 3 4 1 3 5 74 1123101 4

 

Sample Output

Case 1:The minimum cost between station 1 and station 4 is 3.The minimum cost between station 4 and station 1 is 3.Case 2:Station 1 and station 4 are not attainable.

 

Source

2008 “Sunline Cup” National Invitational Contest

题意：给出距离在某个区间时坐车的花费，问从起点到终点的最小花费。

思路：将两个站之间的花费作为建图的边权，求取起点到终点的最短路。

代码：

#include"cstdio"#include"cstring"#include"iostream"#include"algorithm"using namespace std;#define LL long long#define INF 1e18LL x[100];LL maze[105][105];LL n,m;LL l1,l2,l3,l4,c1,c2,c3,c4;int main(){    LL T;    while(scanf("%lld",&T) != EOF)    {        for(LL cas = 1;cas <= T;cas++)        {            scanf("%lld%lld%lld%lld%lld%lld%lld%lld",&l1,&l2,&l3,&l4,&c1,&c2,&c3,&c4);            scanf("%lld%lld",&n,&m);            for(LL i = 1;i <= n;i++)            {                scanf("%lld",&x[i]);            }            for(LL i = 1;i <= n;i++) //按照题意求取两个站之间的花费            {                for(LL j = 1;j <= n;j++)                {                    LL dis = x[i] - x[j];                    if(dis < 0) dis = -dis; //双向                    if(dis == 0) maze[i][j] = 0;                    else if(dis <= l1) maze[i][j] = c1;                    else if(dis <= l2) maze[i][j] = c2;                    else if(dis <= l3) maze[i][j] = c3;                    else if(dis <= l4) maze[i][j] = c4;                    else    maze[i][j] = INF;                }            }            //站i到j的花费不外乎两种：①i到j；②i经由k到j            for(int k = 1;k <= n;k++) //中间站            {                for(int i = 1;i <= n;i++) //枚举起点                {                    for(int j = 1;j <= n;j++) //终点                    {                        if(maze[i][k] != INF && maze[k][j] != INF && maze[i][j] > maze[i][k] + maze[k][j])                        {                            maze[i][j] = maze[i][k] + maze[k][j];                        }                    }                }            }            printf("Case %d:\n",cas);            while(m--)            {                LL st,en;                scanf("%lld%lld",&st,&en);                if(maze[st][en] == INF)                {                    printf("Station %lld and station %lld are not attainable.\n",st,en);                }                else                {                    printf("The minimum cost between station %lld and station %lld is %lld.\n",st,en,maze[st][en]);                }            }        }    }    return 0;}