Submission #1189767

#	Time	Username	Problem	Language	Result	Execution time	Memory
1189767		JooDdae	빌딩 장식 3 (JOI15_building3)	C++20	0 / 100	0 ms	320 KiB

building3

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

int n, a[1001001];

int main() {
	cin.tie(0)->sync_with_stdio(0);
	cin >> n;
	for(int i=1;i<n;i++) cin >> a[i];

	int mx = 0, flag = 0, R = 0;
	for(int i=1;i<n;i++) {
		if(mx+2 < a[i]) return cout << 0, 0;
		if(mx+2 == a[i]) flag++, R = i;
		mx = max(mx, a[i]);
	}

	if(flag > 1) return cout << 0, 0;

	if(flag) {
		int L = 1;
		while(a[L] < a[R]-2) L++;
		return cout << R-L, 0;
	}

	ll ans = 0; mx = 0;
	for(int i=1;i<=n;i++) {
		ans += mx+1, mx = max(mx, a[i]);
	}
	cout << ans - (n-1);
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 30
• Subtask 3: 0 / 60