1131 Subway Map

此题题干略

Sample Input:

4
7 1001 3212 1003 1204 1005 1306 7797
9 9988 2333 1204 2006 2005 2004 2003 2302 2001
13 3011 3812 3013 3001 1306 3003 2333 3066 3212 3008 2302 3010 3011
4 6666 8432 4011 1306
3
3011 3013
6666 2001
2004 3001

Sample Output:

2
Take Line#3 from 3011 to 3013.
10
Take Line#4 from 6666 to 1306.
Take Line#3 from 1306 to 2302.
Take Line#2 from 2302 to 2001.
6
Take Line#2 from 2004 to 1204.
Take Line#1 from 1204 to 1306.
Take Line#3 from 1306 to 3001.

#include<stdio.h>
#include<vector>
#include<algorithm>

using namespace std;

int start;
int final;
int countmax=9999999;
struct Station
{
    int line;
    int id;
}station[10005];
vector<Station> seq[10005];
vector<Station> result;
vector<Station> stops; 
bool flag[10005];
int submin;

void dfs(int s,int count)
{
    if(s==final)
    {
        int sub=0;
        if(countmax>count)
        {
            result=stops;
            countmax=count;
            for(int i=1;i<stops.size();i++)
            {
                if(stops[i].line!=stops[i-1].line)
                {
                    sub++;
                }
            }
            submin=sub;
            
        }
        if(countmax==count)
        {
            for(int i=1;i<stops.size();i++)
            {
                if(stops[i].line!=stops[i-1].line)
                {
                    sub++;
                }
            }
            if(sub<submin)
            {
                result=stops;
                submin=sub;
            }
        }
        return;
    }
    for(int i=0;i<seq[s].size();i++)
    {
        if(flag[seq[s][i].id]==false)
        {
            flag[seq[s][i].id]=true;
            stops.push_back(seq[s][i]);
            dfs(seq[s][i].id,count+1);
            stops.pop_back();
            flag[seq[s][i].id]=false;
        }
    }
}
int main()
{
    int linenum;
    scanf("%d",&linenum);
    for(int i=1;i<=linenum;i++)
    {
        int potnum;
        scanf("%d",&potnum);
        for(int j=0;j<potnum;j++)
        {
            int temp;
            scanf("%d",&temp); 
            station[j].id=temp;
            station[j].line=i;
            if(j!=0)
            {
                seq[station[j].id].push_back(station[j-1]);
                seq[station[j-1].id].push_back(station[j]);
            }
            
        }
    }
    int cxnum;
    scanf("%d",&cxnum);
    for(int i=0;i<cxnum;i++)
    {
        scanf("%d %d",&start,&final);
        countmax=9999999;
        dfs(start,0);
        printf("%d\n",countmax);
        int lineout=result[0].line;
        int id=start;
        for(int i=0;i<result.size();i++)
        {
            if(lineout!=result[i].line)
            {
                printf("Take Line#%d from %04d to %04d.\n",lineout,id,result[i-1].id);
                lineout=result[i].line;
                id=result[i-1].id;
            }

        }
        printf("Take Line#%d from %04d to %04d.\n",lineout,id,final);
        
    }
    
}