Submission #1241895

#	Time	Username	Problem	Language	Result	Execution time	Memory
1241895		khanhtt	Stove (JOI18_stove)	C++20	100 / 100	13 ms	1864 KiB

stove

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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, k;
    cin >> n >> k;
    vector<ll> A(n);
    for(int i = 0; i < n; i++){
        cin >> A[i];
    }

    if(k >= n){
        // You can put each element in its own segment
        cout << n << "\n";
        return 0;
    }

    sort(A.begin(), A.end());

    // Compute the n-1 gaps between consecutive points:
    vector<ll> gaps;
    gaps.reserve(n-1);
    for(int i = 1; i < n; i++){
        gaps.push_back(A[i] - A[i-1]);
    }

    // Sort gaps descending:
    sort(gaps.begin(), gaps.end(), greater<ll>());

    // Base cost is covering everything in one segment:
    ll cost = (A[n-1] - A[0] + 1);

    // Subtract the (k-1) largest (gap - 1) savings:
    for(int i = 0; i < k-1; i++){
        cost -= (gaps[i] - 1);
    }

    cout << cost << "\n";
    return 0;
}

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