Skip to content
Related Articles

Related Articles

Save Article
Improve Article
Save Article
Like Article

Count squares of size K inscribed in a square of size N

  • Difficulty Level : Medium
  • Last Updated : 16 Apr, 2021

Given two integers N and K, the task is to find the number of squares of size K that is inscribed in a square of size N.

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with experts, please refer DSA Live Classes for Working Professionals and Competitive Programming Live for Students.

Examples:



Input: N = 4, K = 2
Output: 9
Explanation:
There are 9 squares of size 2 inscribed in a square of size 4.

Input: N = 5, K = 3
Output: 9
Explanation:
There are 9 squares of size 3 inscribed in a square of size 5.

Approach: The key observation to solve the problem is that the total number of squares in a square of size N is (N * (N + 1)* (2*N + 1)) / 6. Therefore, the total number of squares of size K possible from a square of size N are:

(N - K + 1) * (N - K + 1)

Below is the implementation of the above approach:

C++




// C++ implementation of the
// above approach
 
#include <iostream>
using namespace std;
 
// Function to calculate the number
// of squares of size K in a square
// of size N
int No_of_squares(int N, int K)
{
    // Stores the number of squares
    int no_of_squares = 0;
 
    no_of_squares
        = (N - K + 1) * (N - K + 1);
 
    return no_of_squares;
}
 
// Driver Code
int main()
{
    // Size of the
    // bigger square
    int N = 5;
 
    // Size of
    // smaller square
    int K = 3;
    cout << No_of_squares(N, K);
    return 0;
}

Java




// Java implementation of the
// above approach
import java.util.*;
class GFG{
 
// Function to calculate the
// number of squares of size
// K in a square of size N
static int No_of_squares(int N,
                         int K)
{
  // Stores the number
  // of squares
  int no_of_squares = 0;
 
  no_of_squares = (N - K + 1) *
                  (N - K + 1);
 
  return no_of_squares;
}
 
// Driver Code
public static void main(String[] args)
{
  // Size of the
  // bigger square
  int N = 5;
 
  // Size of
  // smaller square
  int K = 3;
  System.out.print(No_of_squares(N, K));
}
}
 
// This code is contributed by Princi Singh

Python3




# Python3 implementation of the
# above approach
 
# Function to calculate the
# number of squares of size
# K in a square of size N
def No_of_squares(N, K):
   
    # Stores the number
    # of squares
    no_of_squares = 0;
    no_of_squares = (N - K + 1) * (N - K + 1);
    return no_of_squares;
 
# Driver Code
if __name__ == '__main__':
   
    # Size of the
    # bigger square
    N = 5;
 
    # Size of
    # smaller square
    K = 3;
    print(No_of_squares(N, K));
 
# This code is contributed by 29AjayKumar

C#




// C# implementation of the
// above approach
using System;
 
class GFG{
 
// Function to calculate the
// number of squares of size
// K in a square of size N
static int No_of_squares(int N, int K)
{
     
    // Stores the number
    // of squares
    int no_of_squares = 0;
     
    no_of_squares = (N - K + 1) *
                    (N - K + 1);
     
    return no_of_squares;
}
 
// Driver Code
public static void Main(String[] args)
{
     
    // Size of the
    // bigger square
    int N = 5;
     
    // Size of
    // smaller square
    int K = 3;
     
    Console.Write(No_of_squares(N, K));
}
}
 
// This code is contributed by Amit Katiyar

Javascript




<script>
 
// JavaScript program for
// the above approach
 
// Function to calculate the
// number of squares of size
// K in a square of size N
function No_of_squares(N, K)
{
  // Stores the number
  // of squares
  let no_of_squares = 0;
  
  no_of_squares = (N - K + 1) *
                  (N - K + 1);
  
  return no_of_squares;
}
 
// Driver code
 
    // Size of the
  // bigger square
  let N = 5;
  
  // Size of
  // smaller square
  let K = 3;
  document.write(No_of_squares(N, K));
   
  // This code is contributed by splevel62.
</script>
Output: 
9

Time Complexity: O(1) 
Auxiliary Space: O(1)




My Personal Notes arrow_drop_up
Recommended Articles
Page :