oj.uz

답안 #473749

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
473749 2021-09-16T04:29:36 Z ntabc05101 Mag (COCI16_mag) C++14
12 / 120
 634 ms 262148 KB 
#include<bits/stdc++.h>
using namespace std;

const int MAX = 1000000;

int n;
int i, gc;

bool cmp(const pair<int, int> &a, const pair<int, int> &b) {
  return (long long)a.first * b.second < (long long)a.second * b.first;
}

int p[MAX];
int dpup[MAX], dpdown[MAX];
vector<int> adj[MAX];
pair<int, int> res = {1e9, 1};

void dfsdown(int node, int par) {
  vector<int> L, R;
  L.push_back(0);
  for (auto &it : adj[node]) {
    if (it != par) {
      dfsdown(it, node);
      L.push_back(max(L.back(), p[it] == 1 ? dpdown[it] + 1 : 0));
    }
  }

  R.push_back(0);
  for (i = (int)adj[node].size() - 1; i >= 0; i--) {
    auto &it = adj[node][i];
    if (it != par) {
      dpup[it] = (p[node] == 1 ? (1 + max(L[L.size() - R.size() - 1], R.back())): 0);
      R.push_back(max(R.back(), p[it] == 1 ? dpdown[it] + 1 : 0));
    }
  }

  dpdown[node] = L.back();
  L.clear(); R.clear();
}

pair<int, int> tmp, a;
int mx, val;

void dfsup(int node, int par) {
  if (node) {
    dpup[node] = (p[par] == 1 ? max(dpup[node], 1 + dpup[par]) : 0);
  }

  a = {p[node], 1};
  if (cmp(a, res)) {
    res = a;
  }
  mx = dpup[node];

  for (auto &it : adj[node]) {
    if (it == par) {
      continue;
    }

    val = (p[it] == 1 ? dpdown[it] + 1 : 0);
    tmp = {p[node], 1 + mx + val};
    if (cmp(tmp, res)) {
      res = tmp;
    }
    mx = max(mx, val);
    dfsup(it, node);
  }
}

int main() {
  if (fopen("input.txt", "r")) {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
  }

  cin.tie(0)->sync_with_stdio(0);

  cin >> n;
  int a, b;
  for (i = 0; i < n - 1; i++) {
    cin >> a >> b;
    a--; b--;
    adj[a].push_back(b);
    adj[b].push_back(a);
  }

  for (i = 0; i < n; i++) {
    cin >> p[i];
  }

  dfsdown(0, -1);
  dfsup(0, -1);

  gc = __gcd(res.first, res.second);
  cout << res.first / gc << "/" << res.second / gc << endl;

  return 0;
}

Compilation message

mag.cpp: In function 'int main()':
mag.cpp:72:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
mag.cpp:73:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 23884 KB Output is correct
2 Incorrect 13 ms 23872 KB Output isn't correct

Subtask #2
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 14 ms 23780 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
12.0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 512 ms 140408 KB Output is correct

Subtask #4
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 23756 KB Output is correct
2 Runtime error 548 ms 262148 KB Execution killed with signal 9

Subtask #5
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 634 ms 262148 KB Execution killed with signal 9

Subtask #6
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 569 ms 67692 KB Output is correct
2 Incorrect 405 ms 56512 KB Output isn't correct

Subtask #7
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 524 ms 72136 KB Output is correct
2 Incorrect 100 ms 28996 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #8
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 144 ms 28952 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #9
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 501 ms 68156 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #10
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 579 ms 69120 KB Output isn't correct
2 Halted 0 ms 0 KB -