Yes I am maintaining a 2 -d vector but in this example I am not able to retrieve all components

My sample code

const int MAXN = 1e5 + 5; const int MAXM = 1e5 + 5;

int N, M, timer, compid;

vector<pair<int, int>> g[MAXN]; bool used[MAXN], isBridge[MAXM]; int comp[MAXN], tin[MAXN], minAncestor[MAXN];

vector tree[MAXN]; // Store 2-edge-connected component tree.(Bridge tree).

void dfs(int v, int p) { tin[v] = minAncestor[v] = ++timer; used[v] = 1; for(auto &e: g[v]) { int to, id; tie(to, id) = e; if(to == p) continue; if(used[to]) { minAncestor[v] = min(minAncestor[v], tin[to]); } else { dfs(to, v); minAncestor[v] = min(minAncestor[v], minAncestor[to]); if(minAncestor[to] > tin[v]) { isBridge[id] = true; } } } }

void dfs1(int v, int p) { used[v] = 1; comp[v] = compid; for(auto &e: g[v]) { int to, id; tie(to, id) = e;

if(isBridge[id]) { // avoid traversing from this edge. so we get full component.
        continue;
    }
    if(used[to]) {
        continue;
    }
    dfs1(to, v);
}

}

vector<pair<int, int>> edges;

void addEdge(int from, int to, int id) { g[from].push_back({to, id}); g[to].push_back({from, id}); edges[id] = {from, to}; }

void initB() {

for(int i = 0; i <= compid; ++i)
    tree[i].clear();
for(int i = 1; i <= N; ++i)
    used[i] = false;
for(int i = 1; i <= M; ++i)
    isBridge[i] = false;

timer = 0;
compid = 0;

}

void bridge_tree() {

initB();

dfs(1, -1); //Assuming graph is connected.

for(int i = 1; i <= N; ++i)
    used[i] = 0;

for(int i = 1; i <= N; ++i) {
    if(!used[i]) {
        dfs1(i, -1);
        ++compid;
    }
}

for(int i = 1; i <= M; ++i) {
    if(isBridge[i]) {
        int u, v;
        tie(u, v) = edges[i];
        // connect two componets using edge.
        tree[comp[u]].push_back(comp[v]);
        tree[comp[v]].push_back(comp[u]);
    }
}

}

void init() { edges.clear(); edges.resize(M + 1); for(int i = 1; i <= N; ++i) g[i].clear(); }

void solve() { cin >> N >> M;

init();

for(int i = 1; i <= M; ++i) {
    int u, v;
    cin >> u >> v; addEdge(u, v, i);
}

bridge_tree();

}