Cod sursa(job #1901513)

Utilizator oldatlantianSerban Cercelescu oldatlantian Data 4 martie 2017 00:20:01
Problema Stramosi Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.98 kb
#include <bits/stdc++.h>
using namespace std;

ifstream fi("stramosi.in");
ofstream fo("stramosi.out");

const int NMAX = 250005;

vector<int> ant;
int n, m;

vector<pair<int, int>> qs[NMAX];
vector<int> tree[NMAX];

void dfs(int u) {
    vector<pair<int, int>> stk;
    stk.emplace_back(u, 0);

    while (!stk.empty()) {
        if (stk.back().second == 0)
        for (auto q: qs[stk.back().first])
            ant[q.first] = stk[ max(0, int(stk.size()) - q.second - 1) ].first;

        if (stk.back().second < tree[stk.back().first].size())
            stk.emplace_back(tree[stk.back().first][stk.back().second++], 0);
        else
            stk.pop_back(); } }

int main() {
    int far, nod, k;

    fi >> n >> m;
    for (int i = 1; i <= n; ++i) {
        fi >> far;
        tree[far].push_back(i); }

    ant.resize(m);
    for (int i = 0; i < m; ++i) {
        fi >> nod >> k;
        qs[nod].emplace_back(i, k); }

    dfs(0);

    for (auto i: ant)
        fo << i << '\n';

    return 0; }