Submission #707770

#	Time	Username	Problem	Language	Result	Execution time	Memory
707770		penguin133	Bigger segments (IZhO19_segments)	C++17	0 / 100	0 ms	340 KiB

segments

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, A[500005], P[500005];
pi dp[3005];

struct node{
	int s, e, m;
	node *l, *r;
	pi val;
	node(int _s, int _e){
		s = _s, e = _e, m = (s + e) >> 1;
		val = {-1e18, -1e18};
		l = r = nullptr;
	}
	
	void mc(){
		if(l != nullptr)return;
		if(s == e)return;
		l = new node(s, m);
		r = new node(m+1, e);
	}
	
	void upd(int a, pi b){
		if(s == e) val = max(val, b);
		else{
			mc();
			if(a <= m)l->upd(a, b);
			else r->upd(a, b);
			val = max(l->val, r->val);
		}
	}
	
	pi qry(int a, int b){
		if(s == a && b == e)return val;
		if(l == nullptr)return val;
		if(b <= m)return l->qry(a, b);
		else if(a > m)return r->qry(a, b);
		else return max(l->qry(a, m), r->qry(m+1, b));
	}
	
}*root;



void solve(){
	root = new node(0, 1e15);
	cin >> n;
	for(int i=1;i<=n;i++)cin >> A[i], P[i] = P[i-1] + A[i];
	root->upd(0, {0, 0});
	for(int i=1;i<=n;i++){
		dp[i] = {-1e18, -1e18};
		dp[i] = root->qry(0, P[i] - 1);
		dp[i].fi++;
		dp[i].se -= P[i];
		root->upd(P[i] - dp[i].se, {dp[i].fi, P[i]});
		/*
		for(int j = i - 1; j >= 0; j--){
			if(-dp[j].se <= P[i] - P[j])dp[i] = max(dp[i], {dp[j].fi + 1, P[j] - P[i]});
		}
		*/
	}
	cout << dp[n].fi;
}

main(){
	ios::sync_with_stdio(0);cin.tie(0);
	int tc = 1;
	//cin >> tc;
	for(int tc1=1;tc1<=tc;tc1++){
		// cout << "Case #" << tc1 << ": ";
		solve();
	}
}

Compilation message (stderr)

segments.cpp:76:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   76 | main(){
      | ^~~~

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