Submission #497563

#	Time	Username	Problem	Language	Result	Execution time	Memory
497563		kingline	Bigger segments (IZhO19_segments)	C++17	100 / 100	67 ms	16452 KiB

segments

/*#pragma GCC optimize("O3")
#pragma GCC target ("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")*/
#include <bits/stdc++.h>
#pragma GCC optimize ("unroll-loops,Ofast,O3")
#pragma GCC target("avx,avx2,fma")
//#define file(data) freopen(data".in", "r", stdin); freopen(data".out", "w", stdout);
#define pb push_back
//#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define all(data) data.begin() , data.end()
#define endl '\n'
//freopen("nenokku_easy.in", "r", stdin);
//freopen("nenokku_easy.out", "w", stdout);
#define int long long
#define pii pair < int, int >
#define pll pair < long long, long long >

using namespace std;

typedef long long ll;
const int N = 1e6 + 5;
const int M = 3005;
const int mod = 1e9 + 7;

int n, a[N], pref[N];
pair < int, int > dp[N];

main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    //file("pieaters");
    cin >> n;
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
    }
    for(int i = 1; i <= n; i++) {
        dp[i].second = max(dp[i - 1].second, dp[i].second);
        dp[i].first = dp[dp[i].second].first + 1;
        int l = i + 1, r = n;
        while(l < r) {
            int md = (l + r) / 2;
            if(pref[md] >= 2 * pref[i] - pref[dp[i].second]) {
                r = md;
            } else {
                l = md + 1;
            }
        }
        if(pref[l] >= 2 * pref[i] - pref[dp[i].second]) dp[l].second = max(dp[l].second, i);
    }
    cout << dp[n].first;
}

Compilation message (stderr)

segments.cpp:30:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   30 | main() {
      | ^~~~

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