Submission #1117479

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117479		secretwood01	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++17	100 / 100	31 ms	10192 KiB

Main

// Find the max number of rounds you need for each prefix, and each suffix, then for each position, check the max of the prefix and suffix.
 
#include <bits/stdc++.h>
using namespace std;
 
int N;
 
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> N;
	vector<long long> arr(N+1);
	for (int i = 1; i <= N; i++) {
		cin >> arr[i];
	}
	vector<long long> prefixAdd(N+1), prefixVal(N+1);
	for (int i = 1; i <= N; i++) {
		prefixVal[i] = arr[i]+prefixAdd[i-1];
		prefixAdd[i] = prefixAdd[i-1];
		if (prefixVal[i] <= prefixVal[i-1]+1) {
			prefixAdd[i] += (prefixVal[i-1]-prefixVal[i]+1);
			prefixVal[i] = prefixVal[i-1]+1;
		}
	}
	vector<long long> suffixAdd(N+2), suffixVal(N+2);
	for (int i = N; i >= 1; i--) {
		suffixVal[i] = arr[i]+suffixAdd[i+1];
		suffixAdd[i] = suffixAdd[i+1];
		if (suffixVal[i] <= suffixVal[i+1]+1) {
			suffixAdd[i] += (suffixVal[i+1]-suffixVal[i]+1);
			suffixVal[i] = suffixVal[i+1]+1;
		}
	}
	long long ans = LLONG_MAX;
	for (int i = 1; i <= N; i++) {
		ans = min(ans, max(prefixAdd[i], suffixAdd[i]));
	}
	cout << ans << "\n";
}

• Subtask 1: 40 / 40
• Subtask 2: 60 / 60