Submission #977836

#	Time	Username	Problem	Language	Result	Execution time	Memory
977836		phoenix	Safety (NOI18_safety)	C++17	3 / 100	2076 ms	1968 KiB

safety

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int N = 200'200;

int n;

ll h;
ll s[N];


void solve() {
    cin >> n >> h;
    for (int i = 1; i <= n; i++)
        cin >> s[i];
    
    set<ll> t1, t2;
    t1.insert(s[1]);
    t2.insert(s[1]);
    ll base = 0;

    for (int i = 2; i <= n; i++) {
        set<ll> st;
        {
            for (ll c : t1) st.insert(c - h);
            t1 = st;
            st.clear();
        }
        {
            for (ll c : t2) st.insert(c + h);
            t2 = st;
            st.clear();
        }
        ll l = *(--t1.end()), r = *t2.begin();
        if (l <= s[i] && s[i] <= r) {
            t1.insert(s[i]);
            t2.insert(s[i]);
        } else
        if (s[i] < l) {
            t1.insert(s[i]);
            t1.erase(l);
            t2.insert(l);
            base += l - s[i];
        } else 
        if (r < s[i]) {
            t2.insert(s[i]);
            t2.erase(r);
            t1.insert(r);
            base += s[i] - r;
        }
    }
    cout << base;
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int test_cases = 1;
    // cin >> test_cases;
    while (test_cases-->0) {
        solve();
    }
}

• Subtask 1: 3 / 3
• Subtask 2: 0 / 4
• Subtask 3: 0 / 9
• Subtask 4: 0 / 5
• Subtask 5: 0 / 6
• Subtask 6: 0 / 11
• Subtask 7: 0 / 11
• Subtask 8: 0 / 22
• Subtask 9: 0 / 29