Submission #701651

#	Time	Username	Problem	Language	Result	Execution time	Memory
701651		lto5	Bigger segments (IZhO19_segments)	C++14	37 / 100	427 ms	262144 KiB

segments

#include <bits/stdc++.h>
using namespace std;

int a[100005];
int64_t s[100005];
int f[5005][5005];
int suf[5005][5005];

int64_t get(int l, int r) {
  return s[r] - s[l - 1];
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
#define task "a"
  if (fopen(task ".inp", "r")) {
    freopen(task ".inp", "r", stdin);
    freopen(task ".out", "w", stdout);
  }
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    s[i] = s[i - 1] + a[i];
  }
  memset(f, -1, sizeof(f));
  for (int i = 1; i <= n; i++) {
    int k = i;
    for (int j = i; j >= 2; j--) {
      while (k - 1 >= 1 && get(j, i) >= get(k - 1, j - 1)) {
        k--;
      }
      if (k >= 1 && k <= j - 1 && get(j, i) >= get(k, j - 1)) {
        if (suf[j - 1][k] != -1) f[i][j] = suf[j - 1][k] + 1;
      }
    }
    f[i][1] = 1;
    suf[i][i + 1] = -1;
    for (int j = i; j >= 1; j--) {
      suf[i][j] = max(suf[i][j + 1], f[i][j]);
    }
  }
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++) {
      ans = max(ans, f[i][j]);
    }
  }
  cout << ans;
  return 0;
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:19:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |     freopen(task ".inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
segments.cpp:20:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |     freopen(task ".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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