C++怎么实现一个Tarjan算法求强连通分量_C++图论高级算法与DFS应用

#include <iostream>
#include <vector>
#include <stack>
using namespace std;

const int MAXN = 1e5 + 5;
vector<int> graph[MAXN];
int dfn[MAXN], low[MAXN], timestamp = 0;
bool inStack[MAXN];
stack<int> st;
vector<vector<int>> sccs;

void tarjan(int u) {
    dfn[u] = low[u] = ++timestamp;
    st.push(u);
    inStack[u] = true;

    for (int v : graph[u]) {
        if (!dfn[v]) {
            tarjan(v);
            low[u] = min(low[u], low[v]);
        } else if (inStack[v]) {
            low[u] = min(low[u], dfn[v]);
        }
    }

    if (dfn[u] == low[u]) {
        vector<int> scc;
        while (true) {
            int top = st.top();
            st.pop();
            inStack[top] = false;
            scc.push_back(top);
            if (top == u) break;
        }
        sccs.push_back(scc);
    }
}

int main() {
    int n, m;
    cin >> n >> m;

    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        graph[u].push_back(v);
    }

    for (int i = 1; i <= n; i++) {
        if (!dfn[i]) {
            tarjan(i);
        }
    }

    cout << "Found " << sccs.size() << " SCC(s):\n";
    for (int i = 0; i < sccs.size(); i++) {
        cout << "SCC " << i + 1 << ": ";
        for (int node : sccs[i]) {
            cout << node << " ";
        }
        cout << "\n";
    }

    return 0;
}