Submission #996171

#	Time	Username	Problem	Language	Result	Execution time	Memory
996171		faqinyeager	Stove (JOI18_stove)	C++17	100 / 100	95 ms	12484 KiB

stove

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int n, k;
vector<ll> t;

int main(){
    cin >> n >> k;
    
    t.resize(n);
    
    for(int i = 0; i < n; i++) cin >> t[i];
    
    if(n <= k){
        cout << n;
        return 0;
    }
    
    vector<pair<ll, pair<ll, ll>>> pos(n - 1);
    for(int i = 0; i < n - 1; i++){
        int p = t[i + 1] - t[i];
        pos[i].first = p;
        pos[i].second = {i, i + 1};
    }
 
    sort(pos.begin(), pos.end()); 
    
    vector<pair<pair<ll, ll>, ll>> tmp;
    
    for(int i = 0; i < n - k; i++) tmp.push_back({{pos[i].second.first + 1, pos[i].second.second + 1}, pos[i].first});
            
    int m = tmp.size();
    
    sort(tmp.begin(), tmp.end());
    
    map<ll, ll> parent;
    
    for(int i = 0; i < m; i++){
        if(parent[tmp[i].first.first] == 0) parent[tmp[i].first.second] = tmp[i].first.first;
        else{
            parent[tmp[i].first.second] = parent[tmp[i].first.first];
            parent[tmp[i].first.first] = 0;
        }
    }
    
    ll ans = 0;
    ll last = 0;
    
    for(auto x: parent){
        if(x.first != 0 && x.second != 0){
            ans += t[x.first - 1] - t[x.second - 1] + 1;
            last++;
        }
    }
    
    ans += (k - last);
    
    cout << ans;    
}

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50