SCC Kosaraju C++

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int n;
vector<vector<int>> adj;
vector<vector<int>> adj_t;
vector<bool> vis;
vector<int> comp;
vector<int> order;

void visit(int u)
{
    vis[u] = true;
    for(int v:adj[u]) if(!vis[v]) visit(v);
    order.push_back(u);
}

void assign(int u, int k)
{
    comp[u] = k;
    for(int v:adj_t[u]) if(comp[v]==-1) assign(v, k);
}

void scc()
{
    adj_t.resize(n);
    for(int u=0;u<n;u++) for(int v:adj[u]) adj_t[v].push_back(u);

    vis.resize(n);
    for(int u=0;u<n;u++) if(!vis[u]) visit(u);
    reverse(order.begin(), order.end());

    comp.assign(n, -1);
    int curr = 0;
    for(int u:order) if(comp[u]==-1) assign(u, curr++);
}

int main()
{
    n = 7;
    adj = {
        {5,6},
        {0},
        {1,3,6},
        {4},
        {3},
        {0,4},
        {1,3}
    };
    scc();
    cout << "SCCs: ";
    for(int e:comp) cout << e << ' ';
    cout << '\n';
}