HDU3414 Tour Route(竞赛图寻找哈密顿回路)

#include <iostream>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <queue>
#include <stack>
#include <vector>

using namespace std;
typedef long long LL;
const int maxN = 1000;

inline void read(int&a){char c;while(!(((c=getchar())>=‘0‘)&&(c<=‘9‘)));a=c-‘0‘;while(((c=getchar())>=‘0‘)&&(c<=‘9‘))(a*=10)+=c-‘0‘;}


void Hamilton(int ans[maxN + 7], int map[maxN + 7][maxN + 7], int n, int st){
    int nxt[maxN + 7];
    memset(nxt, -1, sizeof(nxt));
    int head = st;
    for(int i = 1; i <= n; i++){
        if(i == st)continue;
        if(map[i][head]){
            nxt[i] = head;
            head = i;
        }else{
            int pre = head, pos = nxt[head];
            while(pos != -1 && !map[i][pos]){
                pre = pos;
                pos = nxt[pre];
            }
            nxt[pre] = i;
            nxt[i] = pos;
        }
    }
    int cnt = 0;
    for(int i = head; i != -1; i = nxt[i])
        ans[++cnt] = i;
}

int main()
{
    //freopen("input.txt", "r", stdin);
    int N;
    while(~scanf("%d", &N) && N){
        int map[maxN + 7][maxN + 7] = {0};
        for(int i = 1; i <= N; i++){
            for(int j = 1; j <= N; j++){
                int u;
                read(u);
                map[i][j] = u;
            }
        }
        if(N == 1){printf("1\n");continue;}
        int ans[maxN + 7] = {0}, i;
        for(i = 1; i<= N; i++){
            Hamilton(ans, map, N, i);
            if(map[ans[N]][ans[1]]){
                for(int j = 1; j <= N; j++){
                    printf(j == 1 ? "%d":" %d", ans[j]);
                }
                break;
            }
        }
        if(i > N)printf("-1");
        printf("\n");
    }
    return 0;
}