Submission #445018

#	Time	Username	Problem	Language	Result	Execution time	Memory
445018		wind_reaper	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++17	100 / 100	29 ms	6116 KiB

Main

#include <bits/stdc++.h>
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
*/

using namespace std;
// using namespace __gnu_pbds;
using namespace chrono;

// mt19937 rng((int) std::chrono::steady_clock::now().time_since_epoch().count());
/*
template <class T> using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
*/

//***************** CONSTANTS *****************



//***************** GLOBAL VARIABLES *****************



//***************** AUXILIARY STRUCTS *****************



//***************** MAIN BODY *****************

void solve(){
	int N;
	cin >> N;

	int A[N + 2];
	for(int i = 1; i <= N; i++)
		cin >> A[i];

	A[0] = A[N + 1] = 0;

	int64_t pref[N + 2], suf[N + 2];
	// pref[i] -> min number required to fill till ith index from the 1st index
	// suf[i] -> min number required to fill till ith index from the nth index

	pref[0] = 0;
	for(int i = 1; i <= N; i++)
		pref[i] = pref[i - 1] + max(0, A[i - 1] - A[i] + 1);

	suf[N + 1] = 0;
	for(int i = N; i >= 1; --i)
		suf[i] = suf[i + 1] + max(0, A[i + 1] - A[i] + 1);

	int64_t ans = 1'000'000'000'000'000'000;

	for(int i = 1; i <= N; i++)
		ans = min(ans, max(pref[i], suf[i]));

	cout << ans << '\n';
}

//***************** *****************

int32_t main(){
	ios_base::sync_with_stdio(NULL);
	cin.tie(NULL);

	#ifdef LOCAL
		auto begin = high_resolution_clock::now();
	#endif

	int tc = 1;
	// cin >> tc; 
	for (int t = 0; t < tc; t++)
		solve();

	#ifdef LOCAL 
		auto end = high_resolution_clock::now();
		cout << fixed << setprecision(4);
		cout << "Execution Time: " << duration_cast<duration<double>>(end - begin).count() << "seconds" << endl;
	#endif

	return 0;
}

/*
If code gives a WA, check for the following : 
1. I/O format

2. Are you clearing all global variables in between tests if multitests are a thing

3. Can you definitively prove the logic
*/

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