#include <vector>
#include <iostream>

using namespace std;

int floornum(vector<int> arr, int N, int k)
{
    int start =0, end = N-1, index = -1;
    int mid;
    
    while (start <= end)
    {
        mid = (start+end)/2;
        
        if(arr[mid]==k) return mid;
        else if(arr[mid]>k && arr[mid-1]<=k) return (mid-1);
        else if(arr[mid]>k && arr[mid-1]>k) end = mid-1;
        else if(arr[mid]<k) start = mid+1;
        
    }
    if(start == N) index = N-1;
    return index;
}
int main() {
	//code
	int t; cin>>t;
	while(t--)
	{
    	int N, k; cin>>N>>k;
    	vector<int> arr;
    	
    	for(int i=0; i<N; ++i)
    	{
    	    int temp; cin>> temp;
    	    arr.push_back(temp);
    	}
    	
    	cout <<floornum(arr,N,k)<<endl;
	}
	
	return 0;
}

Problem Description

Given a sorted array, arr[] and a value, x, find floor of x in given array. Floor of x is the largest element in arr[] such that the element is smaller than or equal to x. If floor exists, then return index of it, else return -1

• Test Case 1

  Input (stdin)

  3
  7 1
  1 2 8 10 11 12 19
  7 5
  1 2 8 10 11 12 19
  7 10
  1 2 8 10 11 12 19
  

  Expected Output

  0
  1
  3

• Test Case 2

  Input (stdin)

  2
  6 1
  1 8 10 11 12 19
  6 5
  1 2 8 10 12 19
  

  Expected Output

  0
  1