Submission #1287766

#	Time	Username	Problem	Language	Result	Execution time	Memory
1287766		muhammad-ahmad	Line Town (CCO23_day1problem3)	C++20	0 / 25	1 ms	572 KiB

Main

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

#define int long long
#define endl '\n'

void solve(){
	int n; cin >> n;
	int a[n + 2] = {};
	for (int i = 1; i <= n; i++) cin >> a[i];
	vector<int> r(n + 1, -1);
	r[0] = 0;
	for (int i = 1; i <= n; i++){
		if (a[i] == 1 && a[i - 1] == 1){
			if (r[i - 2] == -1) r[i] = -1;
			else r[i] = r[i - 2] + 1;
		}
		if (a[i] != 1) r[i] = r[i - 1];
	}
	
	vector<int> s(n + 2, -1);
	s[n + 1] = 0;
	for (int i = n; i >= 1; i--){
		if (a[i] == -1 && a[i + 1] == -1){
			if (s[i + 2] == -1) s[i] = -1;
			else s[i] = s[i + 2] + 1;
		}
		if (a[i] != -1) s[i] = s[i + 1];
	}
	
	int ans = 1e18;
	for (int i = 1; i <= n + 1; i++){
		if (s[i] != -1 && r[i - 1] != -1){
			ans = min(ans, s[i] + r[i - 1]);
		}
	}
	
	if (ans == 1e18) ans = -1;
	
	cout << ans << endl;
}

signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tc = 1;
	// cin >> tc;
	while (tc--){
		solve();
	}
}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 3
• Subtask 3: 0 / 3
• Subtask 4: 0 / 4
• Subtask 5: 0 / 4
• Subtask 6: 0 / 3
• Subtask 7: 0 / 2
• Subtask 8: 0 / 3