Submission #1203196

#	Time	Username	Problem	Language	Result	Execution time	Memory
1203196		kevinyang	Safety (NOI18_safety)	C++20	100 / 100	115 ms	20744 KiB

safety

#include <bits/stdc++.h>
using namespace std;
#define int long long

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

struct Slope{
    multiset<int>l;
    multiset<int>r;
    int b = 0;
    int delta = 0;
    void balance(){
        while(l.size() < r.size()){
            int fst = *r.begin() + delta;
            r.erase(r.begin());
            l.insert(fst);
        }
        while(l.size() > r.size()){
            int lst = *--l.end();
            r.insert(lst-delta);
            l.erase(--l.end());
        }
    }
    void shiftmin(int x){
        balance();
        delta += x;
    }
    void add(int x){ // multiset insert x two times
        b += x;
        if(l.size() && *--l.end() >= x){
            l.insert(x); l.insert(x);
        }
        else{
            r.insert(x-delta); r.insert(x-delta);
        }
        balance();
    }
    int evalmn(){
        balance();
        int cur = 0;
        int y = b;
        int m = -l.size();
        for(int nxt: l){
            y += m * (nxt-cur);
            cur = nxt;
            m++;
        }
        return y;
    }
};

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    int n,h;
    cin >> n >> h;
    vector<int>a(n+1);
    for(int i = 1; i<=n; i++){
        cin >> a[i];
        a[i] += i*h;
    }
    Slope s;
    for(int i = 1; i<=n; i++){
        if(i>1){
            s.shiftmin(2*h);
        }
        s.add(a[i]);
    }
    cout << s.evalmn() << '\n';
    return 0;
}

• 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