Code:

#include <iostream>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;
#define MAXN 100005
int n, m;
vector <int> p[MAXN];
bool read[MAXN];
void dfs(int x)
{
	cout << x << ' ';
	for (int i = 0; i < p[x].size(); i++)
		if (!read[p[x][i]]) {
			read[p[x][i]] = 1;
			dfs(p[x][i]);
		}
}


void bfs(int x) {
	queue <int> q;
	q.push(x);
	while (!q.empty()) {
		x = q.front();
		q.pop();
		cout << x << " ";
		for (int i = 0; i < p[x].size(); i++)
			if (!read[p[x][i]]) {
				read[p[x][i]] = 1;
				q.push(p[x][i]);
			}
	}
}

int main()
{
	cin >> n >> m;
	for (int i = 1; i <= m; i++)
	{
		int u, v;
		cin >> u >> v;
		p[u].push_back(v);
	}
	read[1] = 1;
	memset (read, 0, sizeof(read));
	dfs(1);
	cout << endl;
	memset (read, 0, sizeof(read));
	bfs(1);
	return 0;
}

dfs是照着书写的，样例通过，提交爆零，不知为何？