Cod sursa(job #1448585)

Utilizator GeiGeiGeorge Cioroiu GeiGei Data 7 iunie 2015 16:20:08
Problema Stramosi Scor 30
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.39 kb
//0010
#include <cstdio>
#include <vector>
#define vi vector<int>::iterator

using namespace std;

vector<int> e[25005];
vector<int> p[25005];

void dfs(int nod, int root) {
    p[nod].push_back(root);
    for (int i = 0; i < p[root].size(); i++) {
        p[nod].push_back(p[root][i]);
    }
    for (int i = 0; i < e[nod].size(); i++) {
        if (e[nod][i] == root) {
            continue;
        }
        dfs(e[nod][i], nod);
    }
}

int main() {
    FILE* fi = fopen("stramosi.in", "rt");
    FILE* fo = fopen("stramosi.out", "wt");

    int n, m;
    fscanf(fi, "%d%d", &n, &m);

    for (int i = 1; i <= n; i++) {
        int aux;
        fscanf(fi, "%d", &aux);
        e[i].push_back(aux);
        e[aux].push_back(i);
    }

    for (int i = 0; i < e[0].size(); i++) {
        int aux1 = e[0][i];
        for (int j = 0; j < e[aux1].size(); j++) {
            int aux2 = e[aux1][j];
            if (aux2 == 0) {
                continue;
            }
            dfs(aux2, aux1);
        }
    }

    for (int i = 0; i < m; i++) {
        int a, b;
        fscanf(fi, "%d%d", &a, &b);
        if (b > p[a].size()) {
            fprintf(fo, "0\n");
        } else {
            if (b == 0) {
                fprintf(fo, "%d\n", a);
            } else {
                fprintf(fo, "%d\n", p[a][b - 1]);
            }
        }
    }

    return 0;
}