Submission #151261

#	Time	Username	Problem	Language	Result	Execution time	Memory
151261		andrew	Bigger segments (IZhO19_segments)	C++17	100 / 100	115 ms	24860 KiB

segments

#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

#pragma GCC optimize("-O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#define fi first
#define se second
#define p_b push_back
#define pll pair<ll,ll>
#define pii pair<int,int>
#define m_p make_pair
#define all(x) x.begin(),x.end()
#define sset ordered_set
#define sqr(x) (x)*(x)
#define pw(x) (1ll << x)

using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
const ll MAXN = 1123456;
const ll N = 2e5;
mt19937_64 rnd(chrono::system_clock::now().time_since_epoch().count());

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

template <typename T> void vout(T s){cout << s << endl;exit(0);}

ll v[MAXN];

int main(){
    ios_base :: sync_with_stdio(0);
    cin.tie(0);

    ll n;
    cin >> n;

    vector <ll> a(n + 1), pref(n + 1);
    vector <pll> dp(n + 1);

    for(int i = 1; i <= n; i++){
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
    }

    dp[0] = {0, 0};
    ll uk = 0;

    ll mx = 0;

    for(int i = 1; i <= n; i++){
        mx = max(mx, v[i]);
        dp[i] = {pref[i] - pref[mx], dp[mx].se + 1};

        if(pref[n] - pref[i] >= dp[i].fi){
            ll l = i + 1, r = n;
            while(l < r){
                ll c = (l + r) >> 1;
                if(pref[c] - pref[i] < dp[i].fi)l = c + 1; else r = c;
            }
            v[l] = max(v[l], ll(i));
        }

    }

    cout << dp[n].se << "\n";

    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:51:8: warning: unused variable 'uk' [-Wunused-variable]
     ll uk = 0;
        ^~

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