DFS输出遍历顺序(邻接链表)

#include<bits/stdc++.h>
using namespace std;
const int N = 1000;

int path[N], h[N], e[N], ne[N], n, m;
int idx = 1;
bool st[N];

int cnt;

void add(int a, int b){
    e[idx] = b;
    ne[idx] = h[a];
    h[a] = idx ++ ;
}

void dfs(int u, int step){
    st[u] = 1;
    path[cnt++] = u;

    for(int i = h[u]; i != -1; i = ne[i]){
        int j = e[i];
        if(!st[j]){
            dfs(j, step + 1);
        }
    }

}

int main(){
    memset(h, -1, sizeof h);
    cin >> n >> m;
    while(m -- ){
        int a, b;
        scanf("%d%d", &a, &b);
        add(a, b);
    }
    dfs(1, 1);
    for(int i = 0; i < cnt; i ++ ) printf("%d ", path[i]);
    return 0;
}