Blackslex and Another RGB Walking

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

using ll = long long;

void setIO() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
}

char colorOf(int dist) {
    static const string colors = "rgb";
    return colors[dist % 3];
}

int residue(char c) {
    if (c == 'r') return 0;
    if (c == 'g') return 1;
    return 2;
}

char chooseColor(const string& s) {
    bool seen[3] = {};
    for (char c : s) seen[residue(c)] = true;

    int cnt = seen[0] + seen[1] + seen[2];
    if (cnt == 1) {
        for (int i = 0; i < 3; i++) {
            if (seen[i]) return colorOf(i);
        }
    }

    for (int missing = 0; missing < 3; missing++) {
        if (!seen[missing]) return colorOf((missing + 1) % 3);
    }

    return 'r';
}

void buildColors(int n, const vector<vector<int>>& adj, string& colors) {
    vector<int> dist(n + 1, -1);
    queue<int> q;
    dist[1] = 0;
    q.push(1);

    while (!q.empty()) {
        int v = q.front();
        q.pop();
        for (int u : adj[v]) {
            if (dist[u] == -1) {
                dist[u] = dist[v] + 1;
                q.push(u);
            }
        }
    }

    colors.assign(n, 'r');
    for (int i = 1; i <= n; i++) colors[i - 1] = colorOf(dist[i]);
}

void solveFirst() {
    int t;
    cin >> t;
    while (t--) {
        int n, m;
        cin >> n >> m;
        vector<vector<int>> adj(n + 1);
        for (int i = 0; i < m; i++) {
            int a, b;
            cin >> a >> b;
            adj[a].push_back(b);
            adj[b].push_back(a);
        }

        string colors;
        buildColors(n, adj, colors);
        cout << colors << '\n';
    }
}

void solveSecond() {
    int t;
    cin >> t;
    while (t--) {
        int q;
        cin >> q;
        while (q--) {
            int d;
            string s;
            cin >> d >> s;
            char want = chooseColor(s);
            for (int i = 0; i < d; i++) {
                if (s[i] == want) {
                    cout << i + 1 << '\n';
                    break;
                }
            }
        }
    }
}

void solveHacked(int t) {
    while (t--) {
        int n, m;
        cin >> n >> m;
        vector<vector<int>> adj(n + 1);
        for (int i = 0; i < m; i++) {
            int a, b;
            cin >> a >> b;
            adj[a].push_back(b);
            adj[b].push_back(a);
        }

        for (int i = 1; i <= n; i++) sort(adj[i].begin(), adj[i].end());

        string colors;
        buildColors(n, adj, colors);

        int q;
        cin >> q;
        while (q--) {
            int v;
            cin >> v;
            int d = (int)adj[v].size();
            string seen;
            seen.reserve(d);

            for (int i = 0; i < d; i++) {
                int p;
                cin >> p;
                int u = adj[v][p - 1];
                seen.push_back(colors[u - 1]);
            }

            char want = chooseColor(seen);
            for (int i = 0; i < d; i++) {
                if (seen[i] == want) {
                    cout << i + 1 << '\n';
                    break;
                }
            }
        }
    }
}

int main() {
    setIO();

    string mode;
    cin >> mode;

    if (mode == "first") {
        solveFirst();
    } else if (mode == "second") {
        solveSecond();
    } else {
        solveHacked(stoi(mode));
    }
}