Submission #547271

#	Time	Username	Problem	Language	Result	Execution time	Memory
547271		pure_mem	Safety (NOI18_safety)	C++14	100 / 100	765 ms	23884 KiB

safety

#pragma GCC optimize("Ofast")

#include <bits/stdc++.h>

#define ll long long
#define ld long double
#define X first
#define Y second
#define MP make_pair

using namespace std;

const int N = 2e5 + 2;
const int INF = 1e9;

int n;
ll h;
ll res, lhs_d, rhs_d;
multiset< ll > lhs_s, rhs_s;

int main () {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	cin >> n >> h;
	
	for(int i = 1;i <= n;i++) {
		ll x;
		cin >> x;
		if(i == 1) {
			lhs_s.insert(x);
			rhs_s.insert(x);
			lhs_d -= h, rhs_d += h;
		}	
		else {
			ll lv = *lhs_s.rbegin() + lhs_d;
		    res += abs(x - lv);
			
			if(*rhs_s.begin() + rhs_d > x) {
				lhs_s.insert(x - lhs_d);
				lhs_s.insert(x - lhs_d);
				
				ll hi = *lhs_s.rbegin() + lhs_d;
				lhs_s.erase(--lhs_s.end());	
				rhs_s.insert(hi - rhs_d);
			}
			else {
				rhs_s.insert(x - rhs_d);
				rhs_s.insert(x - rhs_d);

				ll lo = *rhs_s.begin() + rhs_d;	
				rhs_s.erase(rhs_s.begin());
				lhs_s.insert(lo - lhs_d);
			}

			
			ll lv_n = *lhs_s.rbegin() + lhs_d, rv_n = *rhs_s.begin() + rhs_d;
			if(rv_n < lv) {
				res -= lv - rv_n;
			}
			else if(lv < lv_n){
				res -= lv_n - lv;
			}

			lhs_d -= h, rhs_d += h;
		}
		cerr << res << "\n";
	}

	cout << res;
}

• Subtask 1: 3 / 3
• Subtask 2: 4 / 4
• Subtask 3: 9 / 9
• Subtask 4: 5 / 5
• Subtask 5: 6 / 6
• Subtask 6: 11 / 11
• Subtask 7: 11 / 11
• Subtask 8: 22 / 22
• Subtask 9: 29 / 29