Submission #497427

#	Time	Username	Problem	Language	Result	Execution time	Memory
497427		Ierus	Bigger segments (IZhO19_segments)	C++17	0 / 100	1 ms	204 KiB

segments

#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize ("unroll-loops,Ofast,O3")
#pragma GCC target("avx,avx2,fma")
#define F first
#define S second
#define int long long
#define sz(x) (int)x.size()
#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(),(x).end()
//const int E = 5e5+777;
//const long long inf = 1e18+777;
//const int N = 3e3+777;
//const int MOD = 1e9+7;
int getfast(vector<int> v){
	int n = sz(v);
	int pref[n+2]{}, a[n+2]{};
	for(int i = 0; i < n; ++i) a[i+1] = v[i];
	for(int i = 1; i <= n; ++i) pref[i] = pref[i-1] + a[i];
    auto get = [&](int l, int r){
    	if(l == -1 || r == -1) return -(int)1e9;
    	return pref[r] - pref[l-1];
	};
	auto check = [&](int pos){
		int ans = 1, last = get(1, pos);
		for(int i = pos + 1; i <= n; ++i){
	    	int L = i, R = n, res = -1;
	    	while(L <= R){
	    		int M = (L + R) >> 1LL;
	    		if(last <= get(i, M)){
	    			R = (res = M) - 1;
	    		}else L = M + 1;
	    	}
	    	if(last <= get(i, res)){
	    		++ans;
	    	}else break;
	    	int k = i;
	    	for(; k < res; ++k){
	    		if(last + a[k] <= get(k+1, res)){
	    			last += a[k];
	    		}else break;
	    	}
	    	last = get(k, res);
	    	i = res;
	    }
		return ans;
	};
	int ans = 0;
	for(int i = 1; i <= n; ++i){
//		cerr << i << ": " << check(i) << '\n';
		ans = max(ans, check(i));
	}
    return ans;
}
signed main(){
    ios_base::sync_with_stdio(0),
    cin.tie(0),cout.tie(0);
	int n; cin >> n;
	vector<int> a(n);
	for(auto &i : a) cin >> i;
	cout << getfast(a);
}

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