1837. Isenbaev's Number - Timus

#include <bits/stdc++.h>
#define INF 0x3f3f3f3f

using namespace std;

inline void min_self(int& a, int b) {
    a = min(a, b);
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int N;
    cin >> N;
    vector < vector < string > > t(N + 1, vector < string >(3));
    vector < int > v(N + 1, INF);
    map < string , int > sol;
    queue < int > Q;
    for(int i = 1; i <= N; ++i) {
        bool flag = false;
        for(auto& s : t[i]) {
            cin >> s;
            if(s == "Isenbaev") {
                Q.emplace(i);
                sol[s] = 0;
                flag = true;
                v[i] = 1;
            }
        }
        if(flag)
            for(auto s : t[i])
                if(s != "Isenbaev")
                    sol[s] = 1;
    }
    vector < vector < int > > G(N + 1);
    for(int i = 1; i < N; ++i)
        for(int j = i + 1; j <= N; ++j) {
            bool ok = false;
            for(auto s1 : t[i])
                for(auto s2 : t[j])
                    if(s1 == s2)
                        ok = true;
            if(ok) {
                G[i].emplace_back(j);
                G[j].emplace_back(i);
            }
        }
    while(!Q.empty()) {
        int node = Q.front();
        Q.pop();
        for(int Next : G[node])
            if(v[Next] > v[node] + 1) {
                v[Next] = v[node] + 1;
                Q.emplace(Next);
            }
    }
    for(int i = 1; i <= N; ++i)
        if(v[i] != 1)
            for(auto s : t[i])
                if(sol[s] == 0)
                    sol[s] = v[i];
                else
                    min_self(sol[s], v[i]);
    for(auto x : sol) {
        cout << x.first << ' ';
        if(x.second == INF)
            cout << "undefined\n";
        else
            cout << x.second << '\n';
    }
}