Submission #1119054

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119054		stefanneagu	Cat Exercise (JOI23_ho_t4)	C++17	21 / 100	85 ms	20452 KiB

Main

#include <bits/stdc++.h>

using namespace std;

const int nmax = 2e5 + 1;

int v[nmax], n;

struct AINT {
  int ma[nmax * 4], ai[nmax * 4];

  void build(int nod = 1, int st = 1, int dr = n) {
    if(st == dr) {
      ma[nod] = v[st];
      ai[nod] = st;
      return;
    }
    int mid = (st + dr) / 2;
    build(nod * 2, st, mid);
    build(nod * 2 + 1, mid + 1, dr);
    if(ma[nod * 2] > ma[nod * 2 + 1]) {
      ma[nod] = ma[nod * 2];
      ai[nod] = ai[nod * 2];
    } else {
      ma[nod] = ma[nod * 2 + 1];
      ai[nod] = ai[nod * 2 + 1];
    }
  }

  int query(int l, int r, int nod = 1, int st = 1, int dr = n) {
    if(dr < l || r < st)  {
      return 0;
    }
    if(l <= st && dr <= r) {
      return ai[nod];
    }
    int mid = (st + dr) / 2;
    int i1 = query(l, r, nod * 2, st, mid);
    int i2 = query(l, r, nod * 2 + 1, mid + 1, dr);
    if(v[i1] > v[i2]) {
      return i1;
    }
    return i2;
  }
} st;

int d[nmax];
int maxx = 0;

void solve(int l, int r, int loc, int curr) {
  if(l == r) {
    maxx = max(maxx, curr);
    return;
  }
  int x;
  if(loc == 0) {
    // stanga
    x = st.query(l + 1, r);
    solve(l + 1, x, 1, curr + x - l);
    solve(x, r, 0, curr + x - l);
  } else {
    //dreapta
    x = st.query(l, r - 1);
    solve(l, x, 1, curr + r - x);
    solve(x, r - 1, 0, curr + r - x);
  }
}

int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cin >> n;
  int pn;
  for(int i = 1; i <= n; i++) {
    cin >> v[i];
    if(v[i] == n) {
      pn = i;
    }
  }
  for(int i = 1; i < n; i++) {
    int useless;
    cin >> useless >> useless;
  }
  st.build();
  solve(1, pn, 1, 0);
  solve(pn, n, 0, 0);
  cout << maxx;
  return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int32_t main()':
Main.cpp:86:8: warning: 'pn' may be used uninitialized in this function [-Wmaybe-uninitialized]
   86 |   solve(pn, n, 0, 0);
      |   ~~~~~^~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 0 / 10
• Subtask 5: 0 / 20
• Subtask 6: 0 / 23
• Subtask 7: 0 / 26