Submission #497467

#	Time	Username	Problem	Language	Result	Execution time	Memory
497467		Nalrimet	Bigger segments (IZhO19_segments)	C++17	100 / 100	86 ms	32568 KiB

segments

#include <bits/stdc++.h>

#pragma GCC optimization("g", on)
#pragma GCC optimize ("inline")
#pragma GCC optimization("03")
#pragma GCC optimization("unroll-loops")
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")

#define ll long long
#define pb push_back
#define F first
#define S second

using namespace std;

const int N = 5 * 1e5 + 5;
const int inf = 1e9 + 7;

long long a[N], pref[N], dp[N], mn[N], lef[N];
vector<int> v[N];
int n;

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

	cin >> n;

//8
//7 2 3 5 1 4 6 10
// pref[i] - pref[j] >= pref[j] - pref[k]
// pref[i] >= 2 * pref[j] - pref[k]
	for(ll i = 1; i <= n; ++i){
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
	}
    for(ll i = 1; i <= n; ++i){
        lef[i] = max(lef[i], lef[i - 1]);
        dp[i] = dp[lef[i]] + 1;
        int l, r, mid;
        l = i + 1;
        r = n;
        while(l < r){
            mid = (l + r) / 2;
            if(2 * pref[i] - pref[lef[i]] <= pref[mid]) r = mid;
            else l = mid + 1;
        }
        if(2 * pref[i] - pref[lef[i]] <= pref[l]) lef[l] = max(lef[l], i);
	}

	cout << dp[n];

	return 0;
}

Compilation message (stderr)

segments.cpp:3: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    3 | #pragma GCC optimization("g", on)
      | 
segments.cpp:5: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    5 | #pragma GCC optimization("03")
      | 
segments.cpp:6: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    6 | #pragma GCC optimization("unroll-loops")
      | 
segments.cpp:7: warning: ignoring '#pragma comment ' [-Wunknown-pragmas]
    7 | #pragma comment(linker, "/stack:200000000")
      |

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