제출 #1141220

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1141220		Nurislam	Bigger segments (IZhO19_segments)	C++20	13 / 100	0 ms	328 KiB

segments

#include <bits/stdc++.h>

using namespace std;

signed main(){
	
	int n; cin >> n;
	
	vector<int> a(n);
	for(int  &i : a) cin >> i;
	
	vector<int> pr{0};
	for(int i : a) pr.push_back(pr.back() + i);
	
	vector<int> dp (n + 1, 0), opt(n + 1, 0);
	
	for(int i = 1; i <= n; i++){
		opt[i] = opt[i-1] + a[i-1];
		dp[i] = dp[i-1];
		if( a[i-1] >= opt[i-1] ) dp[i] = dp[i-1]+1, opt[i] = a[i-1];
		
		//cout << dp[i] << ' ' << opt[i] << '\n';
		
		int l = 0, r = i-1, ch = 0;
		while(l <= r){
			int m = (l+r) >> 1;
			
			
			if( dp[m] < dp[i] )
				l = m + 1;
			else if( opt[m] > pr[i] - pr[m] )
				r = m - 1;
			else{
				l = m + 1;
				ch = m;
			}
		}
		
		if( dp[i] < dp[ch] + 1){
			dp[i] = dp[ch] + 1;
			opt[i] = pr[i] - pr[ch];
		}
		
		l = 0; r = i-1; ch = 0;
		while(l <= r){
			int m = (l+r) >> 1;
			
			
			if( dp[m]+1 < dp[i] )
				l = m + 1;
			else if( opt[m] > pr[i] - pr[m] )
				r = m - 1;
			else{
				l = m + 1;
				ch = m;
			}
		}
		
		if( dp[i] == dp[ch] + 1)
			opt[i] = min( opt[i], pr[i] - pr[ch] );
	}
	//for(int i = 0; i <= n; i++)cout << dp[i] << ' ';
	//cout << '\n';
	//for(int i = 0; i <= n; i++)cout << opt[i] << ' ';
	//cout << '\n';
	
	cout << dp[n] << '\n';
};

/*
	Wrong answer on test: 268
	6
	5 4 5 4 11 12
	Correct: 3
	Wrong: 2
*/

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