Cod sursa(job #3262585)

Utilizator ShAwDoRneYNacu Gabriel ShAwDoRneY Data 10 decembrie 2024 20:49:29
Problema Stramosi Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.19 kb
#include <fstream>
#include <vector>
using namespace std;

ifstream fin("stramosi.in");
ofstream fout("stramosi.out");

int dp[18][250005];
vector<int> level(250005, 0);

void DFS(int node, int parent, vector<vector<int>> &tree) {

    level[node] = level[parent] + 1;
    dp[0][node] = parent;

    for(int i=1;  (1 << i) < level[node]; i++) {
        dp[i][node] = dp[i-1][dp[i-1][node]];
    }

    for(auto neighbor : tree[node]) {
        if(neighbor != parent) {
            DFS(neighbor, node, tree);
        }
    }

}

int main() {

    int noNodes, queries;
    fin >> noNodes >> queries;
    
    
    vector<vector<int>> tree(noNodes+1, vector<int>());

    for(int i=1; i<=noNodes; i++) {
        int parent;
        fin >> parent;

        tree[parent].push_back(i);
    }

    for(auto e : tree[0]) {
        DFS(e, 0, tree);
    }

    while(queries--) {
        int node, stramosi;
        fin >> node >> stramosi;

        for(int i=17; i>=0; i--) {
            if((1 << i) <= stramosi) {
                node = dp[i][node];
                stramosi -= (1<<i);
            }
        }

        fout << node << '\n';

    }

    return 0;
}