Submission #287978

#	Time	Username	Problem	Language	Result	Execution time	Memory
287978		errorgorn	Bigger segments (IZhO19_segments)	C++14	100 / 100	69 ms	14472 KiB

segments

//雪花飄飄北風嘯嘯
//天地一片蒼茫

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

int n;
ll arr[500005];
int val[500005];
deque<ii> dq;

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	cin>>n;
	rep(x,1,n+1){
		cin>>arr[x];
		arr[x]+=arr[x-1];
	}
	
	dq.push_back(ii(0,0));
	
	rep(x,1,n+1){
		while (sz(dq)>1 && arr[x]>=dq[1].fi) dq.pop_front();
		
		val[x]=val[dq.front().se]+1;
		ii temp=ii(2*arr[x]-arr[dq.front().se],x);
		while (dq.back().fi>=temp.fi) dq.pop_back();
		dq.push_back(temp);
	}
	
	cout<<val[n]<<endl;
}

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