Submission #651535

#	Time	Username	Problem	Language	Result	Execution time	Memory
651535		KiriLL1ca	Bigger segments (IZhO19_segments)	C++14	0 / 100	1 ms	212 KiB

segments

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define fr first
#define sc second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define pw(x) (1ll << x)
#define sz(x) (int)((x).size())
#define pb push_back
#define endl '\n'
#define mp make_pair

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef unsigned long long ull;

template <typename T> inline bool umin (T &a, const T &b) { if (a > b) { a = b; return 1; } return 0; }
template <typename T> inline bool umax (T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; }
template <typename T>
using oset = tree<T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;

inline void solve () {
        int n; cin >> n;
        vector <int> a (n);
        for (auto &i : a) cin >> i;
        vector <ll> pref (n); pref[0] = a[0];
        for (int i = 1; i < n; ++i) pref[i] = pref[i - 1] + a[i];
        auto get = [&] (int l, int r) { return pref[r] - (l ? pref[l - 1] : 0); };

        vector <int> dp (n), opt (n);
        dp[0] = 1; opt[0] = 0;
        for (int i = 0; i < n; ++i) {
                if (i) {
                        umax(dp[i], dp[i - 1]);
                        umax(opt[i], opt[i - 1]);
                }
                ll sg = get(opt[i], i);
                int pos = lower_bound(all(pref), sg << 1) - pref.begin();
                if (pos < n && pos > i) {
                        umax(dp[pos], dp[i] + 1);
                        umax(opt[pos], i + 1);
                }
        }
        cout << dp[n - 1];
}

signed main() {
        ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
        #ifdef LOCAL
                freopen("input.txt", "r", stdin);
                freopen("output.txt", "w", stdout);
        #endif // LOCAL
        int t = 1; // cin >> t;
        while (t--) solve();
        return 0;
}

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