Cod sursa(job #2890123)

Utilizator matthriscuMatt . matthriscu Data 14 aprilie 2022 17:09:16
Problema Stramosi Scor 80
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.72 kb
#include <stdio.h>
#include <vector>
using std::vector;

int main()
{
	FILE *in = fopen("stramosi.in", "r"), *out = fopen("stramosi.out", "w");

	int n, m;
	fscanf(in, "%d%d", &n, &m);
	
	vector<int> log(n + 1);
	log[1] = 0;
	for (int i = 2; i <= n; ++i)
		log[i] = log[i / 2] + 1;
	
	vector<vector<int>> dp(n + 1, vector<int>(log[n] + 1, 0));

	for (int i = 1; i <= n; ++i)
		fscanf(in, "%d", &dp[i][0]);
	
	for (int i = 1; i <= n; ++i)
		for (int j = 1; j <= log[n]; ++j)
			dp[i][j] = dp[dp[i][j - 1]][j - 1];
	
	while (m--) {
		int p, q;
		fscanf(in, "%d%d", &q, &p);

		int ans = 0;
		for (int i = 0; (1 << i) <= p; ++i)
			if (p & (1 << i))
				ans = q = dp[q][i];

		fprintf(out, "%d\n", ans);
	}

	fclose(in);
	fclose(out);
}