HDU2181(基础dfs)

哈密顿绕行世界问题

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3085    Accepted Submission(s): 1905


Problem Description
一个规则的实心十二面体,它的 20个顶点标出世界著名的20个城市,你从一个城市出发经过每个城市刚好一次后回到出发的城市。 
 
Input
前20行的第i行有3个数,表示与第i个城市相邻的3个城市.第20行以后每行有1个数m,m<=20,m>=1.m=0退出.
 
Output
输出从第m个城市出发经过每个城市1次又回到m的所有路线,如有多条路线,按字典序输出,每行1条路线.每行首先输出是第几条路线.然后个一个: 后列出经过的城市.参看Sample output
 
Sample Input

2 5 20
1 3 12
2 4 10
3 5 8
1 4 6
5 7 19
6 8 17
4 7 9
8 10 16
3 9 11
10 12 15
2 11 13
12 14 20
13 15 18
11 14 16
9 15 17
7 16 18
14 17 19
6 18 20
1 13 19
5
0

Sample Output

1: 5 1 2 3 4 8 7 17 18 14 15 16 9 10 11 12 13 20 19 6 5
2: 5 1 2 3 4 8 9 10 11 12 13 20 19 18 14 15 16 17 7 6 5
3: 5 1 2 3 10 9 16 17 18 14 15 11 12 13 20 19 6 7 8 4 5
4: 5 1 2 3 10 11 12 13 20 19 6 7 17 18 14 15 16 9 8 4 5
5: 5 1 2 12 11 10 3 4 8 9 16 15 14 13 20 19 18 17 7 6 5
6: 5 1 2 12 11 15 14 13 20 19 18 17 16 9 10 3 4 8 7 6 5
7: 5 1 2 12 11 15 16 9 10 3 4 8 7 17 18 14 13 20 19 6 5
8: 5 1 2 12 11 15 16 17 18 14 13 20 19 6 7 8 9 10 3 4 5
9: 5 1 2 12 13 20 19 6 7 8 9 16 17 18 14 15 11 10 3 4 5
10: 5 1 2 12 13 20 19 18 14 15 11 10 3 4 8 9 16 17 7 6 5
11: 5 1 20 13 12 2 3 4 8 7 17 16 9 10 11 15 14 18 19 6 5
12: 5 1 20 13 12 2 3 10 11 15 14 18 19 6 7 17 16 9 8 4 5
13: 5 1 20 13 14 15 11 12 2 3 10 9 16 17 18 19 6 7 8 4 5
14: 5 1 20 13 14 15 16 9 10 11 12 2 3 4 8 7 17 18 19 6 5
15: 5 1 20 13 14 15 16 17 18 19 6 7 8 9 10 11 12 2 3 4 5
16: 5 1 20 13 14 18 19 6 7 17 16 15 11 12 2 3 10 9 8 4 5
17: 5 1 20 19 6 7 8 9 10 11 15 16 17 18 14 13 12 2 3 4 5
18: 5 1 20 19 6 7 17 18 14 13 12 2 3 10 11 15 16 9 8 4 5
19: 5 1 20 19 18 14 13 12 2 3 4 8 9 10 11 15 16 17 7 6 5
20: 5 1 20 19 18 17 16 9 10 11 15 14 13 12 2 3 4 8 7 6 5
21: 5 4 3 2 1 20 13 12 11 10 9 8 7 17 16 15 14 18 19 6 5
22: 5 4 3 2 1 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5
23: 5 4 3 2 12 11 10 9 8 7 6 19 18 17 16 15 14 13 20 1 5
24: 5 4 3 2 12 13 14 18 17 16 15 11 10 9 8 7 6 19 20 1 5
25: 5 4 3 10 9 8 7 6 19 20 13 14 18 17 16 15 11 12 2 1 5
26: 5 4 3 10 9 8 7 17 16 15 11 12 2 1 20 13 14 18 19 6 5
27: 5 4 3 10 11 12 2 1 20 13 14 15 16 9 8 7 17 18 19 6 5
28: 5 4 3 10 11 15 14 13 12 2 1 20 19 18 17 16 9 8 7 6 5
29: 5 4 3 10 11 15 14 18 17 16 9 8 7 6 19 20 13 12 2 1 5
30: 5 4 3 10 11 15 16 9 8 7 17 18 14 13 12 2 1 20 19 6 5
31: 5 4 8 7 6 19 18 17 16 9 10 3 2 12 11 15 14 13 20 1 5
32: 5 4 8 7 6 19 20 13 12 11 15 14 18 17 16 9 10 3 2 1 5
33: 5 4 8 7 17 16 9 10 3 2 1 20 13 12 11 15 14 18 19 6 5
34: 5 4 8 7 17 18 14 13 12 11 15 16 9 10 3 2 1 20 19 6 5
35: 5 4 8 9 10 3 2 1 20 19 18 14 13 12 11 15 16 17 7 6 5
36: 5 4 8 9 10 3 2 12 11 15 16 17 7 6 19 18 14 13 20 1 5
37: 5 4 8 9 16 15 11 10 3 2 12 13 14 18 17 7 6 19 20 1 5
38: 5 4 8 9 16 15 14 13 12 11 10 3 2 1 20 19 18 17 7 6 5
39: 5 4 8 9 16 15 14 18 17 7 6 19 20 13 12 11 10 3 2 1 5
40: 5 4 8 9 16 17 7 6 19 18 14 15 11 10 3 2 12 13 20 1 5
41: 5 6 7 8 4 3 2 12 13 14 15 11 10 9 16 17 18 19 20 1 5
42: 5 6 7 8 4 3 10 9 16 17 18 19 20 13 14 15 11 12 2 1 5
43: 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 2 3 4 5
44: 5 6 7 8 9 16 17 18 19 20 1 2 12 13 14 15 11 10 3 4 5
45: 5 6 7 17 16 9 8 4 3 10 11 15 14 18 19 20 13 12 2 1 5
46: 5 6 7 17 16 15 11 10 9 8 4 3 2 12 13 14 18 19 20 1 5
47: 5 6 7 17 16 15 11 12 13 14 18 19 20 1 2 3 10 9 8 4 5
48: 5 6 7 17 16 15 14 18 19 20 13 12 11 10 9 8 4 3 2 1 5
49: 5 6 7 17 18 19 20 1 2 3 10 11 12 13 14 15 16 9 8 4 5
50: 5 6 7 17 18 19 20 13 14 15 16 9 8 4 3 10 11 12 2 1 5
51: 5 6 19 18 14 13 20 1 2 12 11 15 16 17 7 8 9 10 3 4 5
52: 5 6 19 18 14 15 11 10 9 16 17 7 8 4 3 2 12 13 20 1 5
53: 5 6 19 18 14 15 11 12 13 20 1 2 3 10 9 16 17 7 8 4 5
54: 5 6 19 18 14 15 16 17 7 8 9 10 11 12 13 20 1 2 3 4 5
55: 5 6 19 18 17 7 8 4 3 2 12 11 10 9 16 15 14 13 20 1 5
56: 5 6 19 18 17 7 8 9 16 15 14 13 20 1 2 12 11 10 3 4 5
57: 5 6 19 20 1 2 3 10 9 16 15 11 12 13 14 18 17 7 8 4 5
58: 5 6 19 20 1 2 12 13 14 18 17 7 8 9 16 15 11 10 3 4 5
59: 5 6 19 20 13 12 11 10 9 16 15 14 18 17 7 8 4 3 2 1 5
60: 5 6 19 20 13 14 18 17 7 8 4 3 10 9 16 15 11 12 2 1 5

#include <cstdio>
#include <algorithm>
#include <vector>
#include <string.h>
using namespace std;
const int MAXN=30;
vector<int> mp[MAXN];
int vis[MAXN];
int buf[MAXN];
int start;
int id;
void dfs(int dep,int u)
{
    if(dep==20)
    {
        if(u==start)
        {
            printf("%d:  %d",++id,start);
            for(int i=0;i<dep;i++)
            {
                printf(" %d",buf[i]);
            }
            printf("
");
        }
        return ;
    }
    for(int i=0;i<mp[u].size();i++)
    {
        int v=mp[u][i];
        if(!vis[v])
        {
            vis[v]=1;
            buf[dep]=v;
            dfs(dep+1,v);
            vis[v]=0;
        }
    }
}
int main()
{
    int x;
    while(scanf("%d",&x)!=EOF&&x!=0)
    {
        for(int i=1;i<=20;i++)    mp[i].clear();
        id=0;
        memset(vis,0,sizeof(vis));
        mp[1].push_back(x);
        for(int i=1;i<=2;i++)
        {
            scanf("%d",&x);
            mp[1].push_back(x);
        }
        sort(mp[1].begin(),mp[1].end());
        for(int i=2;i<=20;i++)
        {
            for(int j=0;j<3;j++)
            {
                scanf("%d",&x);
                mp[i].push_back(x);
            }
            sort(mp[i].begin(),mp[i].end());
        }
        scanf("%d",&start);
        dfs(0,start);
    }
    return 0;
}
原文地址:https://www.cnblogs.com/program-ccc/p/5683856.html