Cod sursa(job #1979118)

Utilizator RaresEGaySopterean Adrian RaresEGay Data 9 mai 2017 18:28:07
Problema Stramosi Scor 50
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.96 kb
#include <fstream>
#include <vector>

#define MAXN 250001

using namespace std;

ifstream f ("stramosi.in");
ofstream g ("stramosi.out");

vector < int > v[MAXN];
vector < int > sol[MAXN];
vector < int > stiva;
vector < int > root;

int n, m;

int DFS(int u){
    stiva.push_back(u);

    for(int i = 0; i < v[u].size(); ++i){
        for(int j = stiva.size() - 1; j >= 0; --j)
            sol[v[u][i]].push_back(stiva[j]);
        DFS(v[u][i]);
    }

    stiva.erase(stiva.begin() + stiva.size() - 1);
}

int main(){
    f >> n >> m;
    for(int i = 1; i <= n; ++i){
        int x;
        f >> x;
        if(x) v[x].push_back(i);
        else root.push_back(i);
    }

    for(int i = 0; i < root.size(); ++i){
        DFS(root[i]);
    }

    for(int i = 1; i <= m; ++i){
        int x, y;
        f >> x >> y;
        if(y < sol[x].size() + 1 && !sol[x].empty()) g << sol[x][y-1] << '\n';
        else g << 0 << '\n';
    }
}