Submission #685447

#	Time	Username	Problem	Language	Result	Execution time	Memory
685447		OrazB	Bigger segments (IZhO19_segments)	C++14	100 / 100	93 ms	38588 KiB

segments

#include <bits/stdc++.h>
#define N 500005
#define wr cout << "Continue debugging\n";
#define all(x) (x).begin(), (x).end()
#define ll long long int
#define pii pair <int, int>
#define pb push_back
#define ff first
#define ss second
using namespace std;

ll a[N], mx, n, ind[N];
vector<int> vec;
ll pref[N], dp[N][5];

int calc(int x){
	int l = 0, r = vec.size()-1, pos = 0;
	while(l <= r){
		int md = (l+r)/2;
		if (vec[md] > x) r = md - 1;
		else{
			pos = vec[md];
			l = md + 1;
		}
	}
	return pos;
}

int binary(int i, ll x){
	int l = i+1, r = n, idx=i;
	while(l <= r){
		int md = (l+r)/2;
		if (pref[md]-pref[i] >= x) r = md - 1;
		else{
			idx = md;
			l = md + 1;
		}
	}
	return idx+1;
}

int main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++){
		cin >> a[i];
		pref[i] = pref[i-1]+a[i];
	}
	dp[1][1] = 1;
	dp[1][2] = a[1];
	int pos = binary(1, a[1]);
	if (pos <= n){
		ind[pos] = 1;
		vec.pb(pos);
	}
	for (int i = 2; i <= n; i++){
		int pos = ind[calc(i)];
		if (!pos){
			dp[i][1] = 1;
			dp[i][2] = pref[i];
		}else{
			dp[i][1] = dp[pos][1]+1;
			dp[i][2] = pref[i]-pref[pos];
		}
		pos = binary(i, dp[i][2]);
		if (pos > n) continue;
		ind[pos] = i;
		while(vec.size() and vec.back() >= pos){
			vec.pop_back();
		}
		vec.pb(pos);
	}
	cout << dp[n][1];
}	

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