제출 #1198290

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1198290		aykhn	Bigger segments (IZhO19_segments)	C++20	27 / 100	16 ms	32072 KiB

segments

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define inf 0x3F3F3F3F3F3F3F3F

const int MXN = 2e3 + 5;
const int mod = 1e9 + 7;

int dp[MXN][MXN];

void _()
{
  int n;
  cin >> n;
  int a[n + 1], p[n + 1];
  for (int i = 1; i <= n; i++) cin >> a[i];
  p[0] = 0;
  for (int i = 1; i <= n; i++) p[i] = p[i - 1] + a[i];
  auto sum = [&](int l, int r)
  {
    if (l > r) return 0LL;
    return p[r] - (l ? p[l - 1] : 0LL);
  };
  for (int i = 0; i <= n; i++) for (int j = 0; j <= n; j++) dp[i][j] = -inf;
  dp[0][0] = 0;
  for (int i = 1; i <= n; i++)
  {
    for (int j = i; j >= 0; j--)
    {
      if (j)
      {
        int l = 0, r = j - 1;
        while (l < r)
        {
          int mid = (l + r) >> 1;
          if (sum(mid, j - 1) <= sum(j, i)) r = mid;
          else l = mid + 1;
        }
        if (sum(l, j - 1) <= sum(j, i)) dp[j][i] = dp[l][j - 1] + 1;
      }
      else dp[j][i] = 1;
      if (j + 1 <= i) dp[j][i] = max(dp[j][i], dp[j + 1][i]);
    }
  }
  cout << dp[1][n] << '\n';
}

signed main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t = 1;
  // cin >> t;
  while (t--) _();
}

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27