Submission #1102421

#	Time	Username	Problem	Language	Result	Execution time	Memory
1102421		NotLinux	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++17	0 / 100	1 ms	336 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(v) v.begin() , v.end()
#define sz(a) (int)a.size()
const int inf = 1e18 + 7;
void solve(){
	int n;
	cin >> n;
	int arr[n];
	for(int i = 0;i<n;i++)cin >> arr[i];
	int pre[n]={0} , suf[n]={0};
	int preval[n] , sufval[n];
	preval[0] = arr[0];
	for(int i = 1;i<n;i++){
		pre[i] = pre[i-1] + max(0ll , preval[i-1] + 1 - arr[i]);
		preval[i] = max(arr[i] , preval[i-1] + 1);
	}
	sufval[n-1] = arr[n-1];
	for(int i = n-2;i>=0;i--){
		suf[i] = suf[i+1] + max(0ll , sufval[i+1] + 1 - arr[i]);
		sufval[i] = max(arr[i] , sufval[i+1] + 1);
	}
	int global_ans = inf;
	for(int i = 0;i<n;i++){
		int ans[3];
		ans[0] = (i == 0 ? 0ll : pre[i-1]);
		ans[1] = max(i == 0 ? 0ll : preval[i-1] , i == n-1 ? 0ll : sufval[i+1]) + 1 - arr[i];
		ans[2] = (i == n-1 ? 0ll : suf[i+1]);
		int total = ans[0] + ans[1] + ans[2];
		// cout << "total : " << ans[0] << " " << ans[1] << " " << ans[2] << " = " << total << endl;
		int step = min({ans[0] , ans[1] , ans[2]});
		ans[0] -= step , ans[1] -= step , ans[2] -= step , total -= 2 * step;
		// cout << "step1 : " << step << endl;
		// cout << "total : " << ans[0] << " " << ans[1] << " " << ans[2] << " = " << total << endl;

		step = min(ans[0] , ans[1]);
		ans[0] -= step , ans[1] -= step , total -= step;
		// cout << "step2 : " << step << endl;
		// cout << "total : " << ans[0] << " " << ans[1] << " " << ans[2] << " = " << total << endl;

		step = min(ans[1] , ans[2]);
		ans[1] -= step , ans[2] -= step , total -= step;
		// cout << "step3 : " << step << endl;
		// cout << "total : " << ans[0] << " " << ans[1] << " " << ans[2] << " = " << total << endl;
		// cout << endl;
		global_ans = min(global_ans , total);
	}
	cout << global_ans << endl;
}
signed main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
	int testcase = 1;//cin >> testcase;
	while(testcase--)solve();
	cerr << 1000.0 * clock() / CLOCKS_PER_SEC << " ms" << endl;
}
/*	
 * dont get stuck on one approach , try different ones
 * if you think the implementation is long & messy , change your approach
 * think simple , dont overkill
 */

• Subtask 1: 0 / 40
• Subtask 2: 0 / 60