Window Sort

//Author : Saurav Kalsoor
//Window Sort

#include <bits/stdc++.h>

using namespace std;

vector<int> windowSort(vector<int> arr, int n, int k){

    bool sortIncreasing = true;

    for(int i=0;i < n ;i += k){

        int end = min(i+k, n);

        if(sortIncreasing)
            sort(arr.begin() + i, arr.begin() + end);
        else
            sort(arr.begin() + i, arr.begin() + end, greater<int>());

        sortIncreasing = !sortIncreasing;
    }

    return arr;
}


int main(){
    int n, k;
    cin>>n>>k;
    vector<int> arr(n);

    for(int i=0;i<n;i++)
        cin>>arr[i];

    vector<int> res = windowSort(arr, n, k);

    for(int a : res)
        cout<<a<<" ";
    cout<<endl;

}