Submission #344622

#	Time	Username	Problem	Language	Result	Execution time	Memory
344622		Nurlykhan	Bigger segments (IZhO19_segments)	C++17	37 / 100	200 ms	35820 KiB

segments

#include <bits/stdc++.h>

#define ll long long

using namespace std;

const int N = (int)3000 + 10;
const int mod = (int)1e9 + 7;

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

ll get_sum(int l, int r) {
    return pref[r] - pref[l - 1];
}

int dp[N][N];

int main() {
   // freopen("in.txt", "r", stdin);
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);
        pref[i] = pref[i - 1] + a[i];
    }
    for (int l = 0; l <= n; l++) {
        for (int r = 0; r <= n; r++) {
            dp[l][r] = -mod;
        }
    }
    dp[1][1] = 1;
    for (int l = 1; l <= n; l++) {
        for (int r = l; r <= n; r++) {
            dp[l][r + 1] = max(dp[l][r + 1], dp[l][r]);

            int lo = r + 1, hi = n, ans = -1;
            while (lo <= hi) {
                int mid = (lo + hi) / 2;
                if (get_sum(l, r) > get_sum(r + 1, mid)) {
                    lo = mid + 1;
                } else {
                    ans = mid;
                    hi = mid - 1;
                }
            }

            if (ans != -1)
                dp[r + 1][ans] = max(dp[r + 1][ans], dp[l][r] + 1);
        }
    }
    int ans = 0;
    for (int l = 1; l <= n; l++)
        ans = max(ans, dp[l][n]);
    cout << ans;
    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:22:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   22 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
segments.cpp:24:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 |         scanf("%d", &a[i]);
      |         ~~~~~^~~~~~~~~~~~~

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