Submission #958090

#	Time	Username	Problem	Language	Result	Execution time	Memory
958090		d4xn	Tropical Garden (IOI11_garden)	C++17	49 / 100	21 ms	66760 KiB

garden

#include "garden.h"
#include "gardenlib.h"
#include <bits/stdc++.h>
using namespace std;

const int N = 2e5+5, B = 20;

int n, m, p, q, adj[2][N];
pair<bool, int> dp[2][B][N];

int f(int x, int k) {
  pair<int, int> pr = make_pair(0, x);
  for (int i = 29; i >= 0; i--) {
    if ((k >> i) & 1) {
      pr = dp[pr.first][i][pr.second];
    }
  }
  return pr.second;
}

void count_routes(int n, int m, int p, int R[][2], int q, int G[])
{
  for (int i = 0; i < n; i++) {
    adj[0][i] = adj[1][i] = -1;
  }

  for (int i = 0; i < m; i++) {
    int x = R[i][0];
    int y = R[i][1];

    if (adj[0][x] == -1) {
      adj[0][x] = adj[1][x] = y;
    }
    else if (adj[1][x] == adj[0][x]) {
      adj[1][x] = y;
    }

    if (adj[0][y] == -1) {
      adj[0][y] = adj[1][y] = x;
    }
    else if (adj[1][y] == adj[0][y]) {
      adj[1][y] = x;
    }
  }

  for (int i = 0; i < n; i++) {
    int x = adj[0][i];
    if (x == -1) {
      dp[0][0][i] = make_pair(0, i);
    }
    else {
      dp[0][0][i] = make_pair((adj[0][x] == i), x);
    }

    x = adj[1][i];
    if (x == -1) {
      dp[1][0][i] = make_pair(0, i);
    }
    else {
      dp[1][0][i] = make_pair((adj[0][x] == i), x);
    }
  }

  for (int i = 1; i < B; i++) {
    for (int j = 0; j < n; j++) {
      pair<int, int> mid = dp[0][i-1][j];
      dp[0][i][j] = dp[mid.first][i-1][mid.second];

      mid = dp[1][i-1][j];
      dp[1][i][j] = dp[mid.first][i-1][mid.second];
    }
  }

  cin >> q;
  for (int i = 0; i < q; i++) {
    int x = G[i];

    int ans = 0;
    for (int j = 0; j < n; j++) {
      if (f(j, x) == p) ans++;
    }
    answer(ans);
  }
}

• Subtask 1: 49 / 49
• Subtask 2: 0 / 20
• Subtask 3: 0 / 31