Graph Component

#include <iostream>
#include <vector>

using namespace std;

struct edge{
    int v;
    int w;
    bool only;
};

vector<vector<edge> > edges;
vector<int> parent;
vector<bool> w;
vector<bool> _w;
vector<int> color;
vector<int> history;
int n, m;

int f = 0;
void dump_history(){
    f++;
    cout << "#" << ++f << " : ";
    for (int i = 0; i < history.size(); i++)
        cout << history[i] << " ";
    cout << endl;
}

void dfs(int v, int u){
    _w[v] = true;
    if (w[v]) return;
    //history.push_back(v);
    //dump_history();

    int _buf = parent[v];
    if (parent[v] == -2) parent[v] = u; else
    if (parent[v] != u) parent[v] = -1;

   if (_buf != -1)
   {
        w[v] = true;

        for (int i = 0; i < edges[v].size(); i++){
            int q = edges[v][i].v;
            dfs(q, v);
        }

        w[v] = false;
    }
    //history.pop_back();
}

int _find(int u, int v){
    for (int i = 0; i < edges[u].size(); i++)
        if (edges[u][i].v == v)
            return i;
}

void colorise(int v, int c){
    if (w[v]) return;
    color[v] = c;
    w[v] = true;
    for (int i = 0; i < edges[v].size(); i++){
        if (edges[v][i].only == false) {
            colorise(edges[v][i].v, c);
        }
    }
}

int main()
{
    cin >> n >> m;
    edges.resize(n);
    edge e; e.w = 0; e.only = false;
    int u, v;
    for (int i = 0; i < m; i++){
        cin >> u >> v;
        //u = (rand()*rand()+rand())%n; v = rand()%n;
        u--; v--;
        e.v = v; edges[u].push_back(e);
        e.v = u; edges[v].push_back(e);
    }

    parent.resize(n, -2);
    w.resize(n, false);
    _w.resize(n, false);
    for (int i = 0; i < n; i++){
        if (!(_w[i]))
            dfs(i, -2);
        parent[0] = -1;
    }
/*
    for (int i = 0; i < n; i++){
        cout << parent[i] << " ";
    } cout << endl;*/

    for (int i = 0; i < n; i++){
        if (parent[i] >= 0) {
            int r = _find(i, parent[i]);
            edges[i][r].only = true;
            r = _find(parent[i], i);
            edges[parent[i]][r].only = true;
        }
    }

    color.resize(n, -1);
    int _color = 0;
    for (int i = 0; i < n; i++) w[i] = false;
    for (int i = 0; i < n; i++){
        if (color[i] == -1) {
            _color++;
            colorise(i, _color);
        }
    }

    for (int i = 0; i < n; i++){
        cout << color[i] << " ";
    }
    cout << endl;

    return 0;
}