제출 #854722

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
854722		QuangBui	Cigle (COI21_cigle)	C++14	48 / 100	1029 ms	10172 KiB

cigle

// QuangBuiCP
#ifndef LOCAL
#pragma GCC optimize(3)
#pragma GCC target("avx2")
#endif // LOCAL
#include "bits/stdc++.h"
using namespace std;

#define SZ(a) (int)(a).size()
#define ALL(a) (a).begin(),(a).end()

const int N = 5005;

int n;
int a[N];
int pref[N];
int dp[N][N];

int Brute() {
  int ret = 0;
  for (int mask = 0; mask < (1 << n); ++mask) {
    int cnt = 0;
    set<int> prv, cur;
    int pos = 0, layer = 0;
    bool no = false;
    for (int i = 1; i < n; ++i) {
      int x1 = 0, x2 = 0;
      if (mask >> i & 1) {
        x1 = 1;
      }
      if (mask >> (i - 1) & 1) {
        x2 = 1;
      }
      if (x1 && x2) {
        no = true;
        break;
      }
    }
    if (no) {
      continue;
    }
    for (int i = 0; i < n; ++i) {
      if (mask >> i & 1) {
        layer++;
        prv = cur;
        cur.clear();
      }
      int sign = 1;
      if (layer % 2) {
        sign *= -1;
      }
      pos += sign * a[i + 1];
      if (prv.count(pos) && i != n - 1 && !(mask >> (i + 1) & 1)) {
        cnt++;
      }
      cur.insert(pos);
    }
    ret = max(ret, cnt);
  }
  return ret;
}

signed main() {
#ifndef LOCAL
  cin.tie(nullptr)->sync_with_stdio(false);
#endif // LOCAL

  cin >> n;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
  }
//  if (n <= 20) {
//    cout << Brute() << '\n';
//    return 0;
//  }
  for (int l = 1; l <= n; ++l) {
    for (int r = l; r <= n; ++r) {
      int s = 0, sr = 0;
      int pos = l;
      int cnt = 0;
      for (int i = l - 1; i >= 1; --i) {
        s += a[i];
        while (pos < r && s > sr) {
          sr += a[pos++];
        }
        dp[l][r] = max(dp[l][r], dp[i][l - 1] + cnt);
        if (s == sr) {
          cnt++;
        }
      }
    }
  }
  int ans = 0;
  for (int i = 1; i <= n; ++i) {
    ans = max(ans, dp[i][n]);
  }
  cout << ans << '\n';

#ifdef LOCAL
  cerr << '\n' << clock() << "ms.";
#endif // LOCAL
  return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 0 / 52