oj.uz

Submission #583433

# Submission time Handle Problem Language Result Execution time Memory
583433 2022-06-25T11:06:07 Z 600Mihnea Mousetrap (CEOI17_mousetrap) C++17
25 / 100
 1002 ms 64088 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = (int) 1e6 + 7;
int n, tr, mo;
vector<int> g[N];
int par[N], cost[N];
bool vis[N];

void build_tree(int a, int p = -1) {
  {
    vector<int> Kids;
    for (auto &b : g[a]) {
      if (b != p) {
        Kids.push_back(b);
      }
    }
    g[a] = Kids;
  }
  for (auto &b : g[a]) {
    build_tree(b, a);
  }
  par[a] = p;
}

void build_cost(int a) {
  if (!vis[a]) {
    cost[a] += (int) g[a].size();
  }
  for (auto &b : g[a]) {
    cost[b] += cost[a];
    build_cost(b);
  }
}

void dfs(int a) {
  for (auto &b : g[a]) {
    dfs(b);
  }
  if ((int) g[a].size() == 0) {
    return;
  }
  if ((int) g[a].size() == 1) {
    return;
  }
  assert((int) g[a].size() >= 2);
  vector<int> Values;
  for (auto &b : g[a]) {
    Values.push_back(cost[b]);
  }
  sort(Values.rbegin(), Values.rend());
  assert((int) Values.size() >= 2);
  cost[a] = Values[1];
}

signed main() {
  ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

 /// freopen ("input.txt", "r", stdin);

  cin >> n >> tr >> mo;

  for (int i = 1; i < n; i++) {
    int a, b;
    cin >> a >> b;
    g[a].push_back(b);
    g[b].push_back(a);
  }
  build_tree(tr);
  {
    int current = par[mo];
    while (current != tr) {
      vis[current] = 1;
      current = par[current];
    }
    vis[current] = 1;
  }
  build_cost(tr);
  dfs(tr);

  cout << cost[mo] << "\n";


}

Subtask #1
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 13 ms 23764 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 350 ms 62948 KB Output is correct
2 Correct 315 ms 59020 KB Output is correct
3 Correct 1002 ms 64088 KB Output is correct
4 Correct 491 ms 44000 KB Output is correct
5 Correct 935 ms 64052 KB Output is correct
6 Correct 1002 ms 64080 KB Output is correct

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 13 ms 23764 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 35.0

# Verdict Execution time Memory Grader output
1 Incorrect 13 ms 23764 KB Output isn't correct
2 Halted 0 ms 0 KB -