Submission #158749

#	Time	Username	Problem	Language	Result	Execution time	Memory
158749		koste4ka	Bigger segments (IZhO19_segments)	C++14	100 / 100	121 ms	21032 KiB

segments

//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")

#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>

#define pb push_back
#define F first
#define S second
#define lll long long
#define lld long double

using namespace std;
using namespace __gnu_pbds;

template <typename T>
using ordered_set = tree <T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;

mt19937 gen(chrono::system_clock::now().time_since_epoch().count());

const int N = 1e6 + 11;
const lll M = 1e9 + 7;
const lll M2 = 1e9 + 9;
const int mod = 998244353;
const int rx[8] = {1, 1, -1, -1, -2, -2, 2, 2};
const int ry[8] = {-2, 2, -2, 2, 1, -1, 1, -1};
const lld eps = 1e-7;
const double pi = acos(-1.0);

lll a[N];

lll dp[N];

int k[N];

int ans[N];

lll pref[N];

lll get(int l, int r) {
    lll ans = pref[r];
    if (l) {
        ans -= pref[l - 1];
    }
    return ans;
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    srand(time(0));
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
//    freopen("input.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);
#endif
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
        pref[i] = a[i];
        ans[i] = 1;
        dp[i] = a[i];
        k[i] = 1;
        if (i) {
            dp[i] += dp[i - 1];
            k[i] += k[i - 1];
            pref[i] += pref[i - 1];
        }
    }
    int l, r;
    for (int i = 0; i + 1 < n; ++i) {
        if (dp[i + 1] > dp[i] + a[i + 1]) {
            dp[i + 1] = dp[i] + a[i + 1];
            k[i + 1] = k[i] + 1;
            ans[i + 1] = ans[i];
        }
        l = i + 1;
        r = n - 1;
        while (l + 1 < r) {
            int mid = (l + r) / 2;
            if (get(i + 1, mid) >= dp[i]) {
                r = mid;
            } else {
                l = mid;
            }
        }
        if (get(i + 1, l) < dp[i]) {
            l = r;
        }
        if (get(i + 1, l) >= dp[i]) {
            if (dp[l] > get(i + 1, l)) {
                dp[l] = get(i + 1, l);
                k[l] = l - i;
                ans[l] = ans[i] + 1;
            }
        }
    }
    cout << ans[n - 1];
    return 0;
}

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