#include <bits/stdc++.h>
using namespace std;
#define int long long int
#define double long double
#define print(a) for(auto x : a) cout << x << " "; cout << endl
const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;
inline int power(int a, int b, int mod=M) {
int x = 1;
a %= mod;
while (b) {
if (b & 1) x = (x * a) % mod;
a = (a * a) % mod;
b >>= 1;
}
return x;
}
//_ ***************************** START Below *******************************
// 7 4
// 8 1 4 6 1 5 11
vector<int> a;
int consistency(int n, int k){
sort(begin(a), end(a));
vector<int> prefix(n+1);
for(int i=0; i<n; i++ ){
prefix[i+1] = prefix[i] + a[i];
}
vector<int> sufix(n+1);
for(int i=n-1; i>=0; i--){
sufix[i] = sufix[i+1] + a[i];
}
int ans = INF;
for(int i=k-1; i<n; i++){
int j = i-k+1;
int m1 = j + (k-1)/2;
int m2 = m1+1;
if(k&1){
int leftSum = prefix[m1+1]-prefix[j];
int rightSum = sufix[m1+1] - sufix[i+1];
ans = min(ans, a[m1] - leftSum + rightSum);
}
else{
int leftSum = prefix[m1+1]-prefix[j];
int rightSum = sufix[m1+1] - sufix[i+1];
ans = min(ans, -leftSum + rightSum);
leftSum = prefix[m2+1] - prefix[j];
rightSum = sufix[m2+1] - sufix[i+1];
ans = min(ans, 2*a[m2] - leftSum + rightSum);
}
}
return ans;
}
int practice(int n, int k){
return 0;
}
void solve() {
int n, k;
cin>> n >> k;
a.resize(n);
for(int i=0; i<n; i++) cin >> a[i];
cout << consistency(n, k) << endl;
}
int32_t main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
return 0;
}
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