Submission #524648

#	Time	Username	Problem	Language	Result	Execution time	Memory
524648		DragonO_o	Bigger segments (IZhO19_segments)	C++17	0 / 100	1 ms	332 KiB

segments

#include <bits/stdc++.h>

using namespace std;

#define x first
#define y second
#define pb push_back
#define all(a) a.begin(), a.end()
#define int long long

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<int> vi;
typedef vector<bool> vb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;

const int N = 5e5 + 99;

int a[N], pref[N];
pii dp[N];

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
    }
    if (n <= 1000) {
        int ans = 1;
        for (int i = 1; i <= n; ++i) {
            int cur = i + 1, prev = pref[i], cnt = 1;
            while (cur <= n) {
                int sum = 0;
                for (int j = cur; j <= n; ++j) {
                    sum += a[j];
                    if (sum >= prev) {
                        prev = sum;
                        cnt++;
                        cur = j + 1;
                        break;
                    }
                }
                if (sum < prev) {
                    break;
                }
            }
            ans = max(ans, cnt);
        }
        cout << ans;
    }
    else {
        dp[0] = {0, 0};
        dp[1] = {1, a[1]};
        for (int i = 2; i <= n; ++i) {
            int l = 1, r = i;
            while (l < r) {
                int mid = (l + r + 1) / 2;
                if (pref[i] - pref[mid - 1] < dp[mid - 1].y) {
                    r = mid - 1;
                }
                else {
                    l = mid;
                }
            }
            dp[i] = {dp[l - 1].x + 1, pref[i] - pref[l - 1]};
        }
        cout << dp[n].x;
    }
}

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