图的深度优先搜索和广度优先搜索 C++样例代码

深度优先搜索（DFS）：

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 1005;
vector<int> g[MAXN];
bool vis[MAXN];

void dfs(int u) {
    vis[u] = true;
    cout << u << " ";
    for (int i = 0; i < g[u].size(); i++) {
        int v = g[u][i];
        if (!vis[v]) dfs(v);
    }
}

int main() {
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    dfs(1);
    return 0;
}

广度优先搜索（BFS）：

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 1005;
vector<int> g[MAXN];
bool vis[MAXN];

void bfs(int u) {
    queue<int> q;
    q.push(u);
    vis[u] = true;
    while (!q.empty()) {
        int cur = q.front();
        q.pop();
        cout << cur << " ";
        for (int i = 0; i < g[cur].size(); i++) {
            int v = g[cur][i];
            if (!vis[v]) {
                q.push(v);
                vis[v] = true;
            }
        }
    }
}

int main() {
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    bfs(1);
    return 0;
}