Strange Country II 暴力dfs

这题点的个数（<=50）有限， 所以可以纯暴力DFS去搜索

//#pragma comment(linker, "/STACK:16777216") //for c++ Compiler
#include <stdio.h>
#include <iostream>
#include <fstream>
#include <cstring>
#include <cmath>
#include <stack>
#include <string>
#include <map>
#include <set>
#include <list>
#include <queue>
#include <vector>
#include <algorithm>
#define Max(a,b) (((a) > (b)) ? (a) : (b))
#define Min(a,b) (((a) < (b)) ? (a) : (b))
#define Abs(x) (((x) > 0) ? (x) : (-(x)))
#define MOD 1000000007
#define pi acos(-1.0)

using namespace std;

typedef long long           ll      ;
typedef unsigned long long  ull     ;
typedef unsigned int        uint    ;
typedef unsigned char       uchar   ;

template<class T> inline void checkmin(T &a,T b){if(a>b) a=b;}
template<class T> inline void checkmax(T &a,T b){if(a<b) a=b;}

const double eps = 1e-7      ;
const int N = 210            ;
const int M = 1100011*2      ;
const ll P = 10000000097ll   ;
const int MAXN = 10900000    ;

int n;
int g[110][110], vis[110], ans[110];

void init(){
    memset(g, 0, sizeof(g));
}

bool dfs(int pos, int level){
    ans[level] = pos;
    if(level >= n){
        return true;
    }
    for(int i = 1; i <= n; ++i){
        if(i == pos)    continue;
        if(!vis[i] && g[pos][i]){
            vis[i] = 1;
            if(dfs(i, level + 1)){
                return true;
            }
            vis[i] = 0;
        }
    }
}

int main(){
    std::ios::sync_with_stdio(false);
    int i, j, t, k, u, v, numCase = 0;
    cin >> t;
    while(t--){
        init();
        cin >> n;
        for(i = 1; i <= n * (n - 1) / 2; ++i){
            cin >> u >> v;
            g[u][v] = 1;
        }
        for(i = 1; i <= n; ++i){
            memset(vis, 0, sizeof(vis));
            memset(ans, 0, sizeof(ans));
            vis[i] = 1;
            if(dfs(i, 1))   break;
            vis[i] = 0;
        }
        if(i != n + 1){
            for(i = 1; i < n; ++i){
                cout << ans[i] << ‘ ‘;
            }
            cout << ans[n] << endl;
        } else{
            cout << "Impossible" << endl;
        }
    }

    return 0;
}