MergeSort.java

package coding;

import java.util.Scanner;

class MergeSort 
{ 
    static void merge(int arr[], int l, int m, int r) 
    { 
        
        int n1 = m - l + 1; 
        int n2 = r - m; 
  
        
        int L[] = new int [n1]; 
        int R[] = new int [n2]; 
  
        
        for (int i=0; i<n1; ++i) 
            L[i] = arr[l + i]; 
        for (int j=0; j<n2; ++j) 
            R[j] = arr[m + 1+ j]; 
  
  
       
        int i = 0, j = 0; 
  
      
        int k = l; 
        while (i < n1 && j < n2) 
        { 
            if (L[i] <= R[j]) 
            { 
                arr[k] = L[i]; 
                i++; 
            } 
            else
            { 
                arr[k] = R[j]; 
                j++; 
            } 
            k++; 
        } 
  
        
        while (i < n1) 
        { 
            arr[k] = L[i]; 
            i++; 
            k++; 
        } 
  
       
        while (j < n2) 
        { 
            arr[k] = R[j]; 
            j++; 
            k++; 
        } 
    } 
  
    
    static void sort(int arr[], int l, int r) 
    { 
        if (l < r) 
        { 
            
            int m = (l+r)/2; 
  
           
            sort(arr, l, m); 
            sort(arr , m+1, r); 
  
           
            merge(arr, l, m, r); 
        } 
    } 
  
  
    static void printArray(int arr[]) 
    { 
        int n = arr.length; 
        for (int i=0; i<n; ++i) 
            System.out.print(arr[i] + " "); 
        System.out.println(); 
    } 
  
    
    public static void main(String args[]) 
    { 
        int T;
        Scanner sc=new Scanner(System.in);
        T=sc.nextInt();
        for (int i = 0; i < T; i++) {
			int N,K,count=0;;
			N=sc.nextInt();K=sc.nextInt();
			int arr[]=new int[N];
			for (int j = 0; j < arr.length; j++) {
				arr[j]=sc.nextInt();
			}
			sort(arr, 0, N-1);
			
//			printArray(arr);
			for (int j = N-1; j >=0; j--) {
				if(arr[j]>=arr[N-K]) {
					count++;
				}else {
					break;
				}
			}
			System.out.println(count);
		}
  
       
  
        
    } 
}