Submission #878009

#	Time	Username	Problem	Language	Result	Execution time	Memory
878009		phong	Safety (NOI18_safety)	C++17	100 / 100	41 ms	6428 KiB

safety

#include <bits/stdc++.h>


using ll = long long;
const int nmax = 2e5 + 5;
const int lg = 20;
const int mod = 1e9 + 7;
const ll oo = 1e18;
#define fi first
#define se second
#define pii pair<int, int>
using namespace std;

int n, H;
int a[nmax];

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL), cout.tie(NULL);
//    freopen("code.inp", "r", stdin);
//    freopen("code.out", "w", stdout);
    cin >> n >> H;
    for(int i = 1; i <= n; ++i) cin >> a[i];
    priority_queue<ll> le;
    priority_queue<ll, vector<ll>, greater<ll>> ri;
    ll cur = 0, ans = 0;
    for(int i = 1; i <= n; ++i){
        if(i == 1){
            le.push(a[1]);
            ri.push(a[1]);
        }
        else{
            ll x = le.top(), y = ri.top();
            if(x - cur <= a[i] && a[i] <= y + cur){
                le.push(a[i] + cur);
                ri.push(a[i] - cur);
            }
            else{
                if(a[i] < x - cur){
                    le.push(a[i] + cur);
                    le.push(a[i] + cur);
                    x -= cur;
                    ans += abs(x - a[i]);
                    le.pop();
                    ri.push(x - cur);
                }
                else{
                    ri.push(a[i] - cur);
                    ri.push(a[i] - cur);
                    y += cur;
                    ans += abs(y - a[i]);
                    ri.pop();
                    le.push(y + cur);
                }
            }
        }
        cur += H;
    }
    cout << ans;
}
/*
10
4.0530 1.2670
4.3790 2.1420
1.9230 2.1920
3.3740 1.0850
0.9690 3.4510
1.5270 0.5160
4.3860 1.3360
4.5560 1.5050
4.9650 1.8120
0.6250 0.4820

*/

• 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