# Finding the converging element of the diagonals in a square matrix

Given a square matrix, the task is to find the element of the matrix where the right and the left diagonal of this square matrix converge.

Example:

Input: n = 5, matrix =
[ 1 2 3 4 5
5 6 7 8 6
9 5 6 8 7
2 3 5 6 8
1 2 3 4 5 ]
Output: 6

Input: n = 4, matrix =
[ 1 2 3 4
5 6 7 8
9 0 1 2
4 5 6 1 ]
Output: NULL
Here there no converging element at all.
Hence the answer is null.

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach:

• If the number of rows and column of the matrix are even, then we just print NULL because there would be no converging element in the case of even number of rows and column.
• If the number of rows and column of the matrix are odd, find the mid-value of n as
mid = n/2
• The arr[mid][mid] itself is the converging diagonal element.

Below is the implementation of the above approach:

## C++

 // C++ program to find the converging element // of the diagonals in a square matrix    #include #include #include    // Driver code int main() {     int n = 5;     int a[][5] = { { 1, 2, 3, 4, 5 },                    { 5, 6, 7, 8, 6 },                    { 9, 5, 6, 8, 7 },                    { 2, 3, 5, 6, 8 },                    { 1, 2, 3, 4, 5 } };        int convergingele, mid;     int i, j;        // If n is even, then convergence     // element will be null.     if (n % 2 == 0) {         printf("NULL\n");     }        else {         // finding the mid         mid = n / 2;            // finding the converging element         convergingele = a[mid][mid];            printf("%d\n", convergingele);     } }

## Java

 // Java program to find the converging element // of the diagonals in a square matrix class GFG {        // Driver code     public static void main(String args[])      {         int n = 5;         int a[][] = {{1, 2, 3, 4, 5},                      {5, 6, 7, 8, 6},                      {9, 5, 6, 8, 7},                      {2, 3, 5, 6, 8},                      {1, 2, 3, 4, 5}};            int convergingele, mid;         int i, j;            // If n is even, then convergence         // element will be null.         if (n % 2 == 0)          {             System.out.printf("NULL\n");         }          else          {             // finding the mid             mid = n / 2;                // finding the converging element             convergingele = a[mid][mid];                System.out.printf("%d\n", convergingele);         }     } }    // This code is contributed by Rajput-Ji

## Python3

 # Python3 program to find the converging element # of the diagonals in a square matrix    # Driver code n = 5 a = [[ 1, 2, 3, 4, 5 ],      [ 5, 6, 7, 8, 6 ],      [ 9, 5, 6, 8, 7 ],      [ 2, 3, 5, 6, 8 ],      [ 1, 2, 3, 4, 5 ]]    # If n is even, then convergence # element will be null. if (n % 2 == 0):     print("NULL") else :            # finding the mid     mid = n // 2        # finding the converging element     convergingele = a[mid][mid]        print(convergingele)    # This code is contributed by Mohit Kumar

## C#

 // C# iprogram to find the converging element // of the diagonals in a square matrix using System;        class GFG {        // Driver code     public static void Main(String []args)      {         int n = 5;         int [,]a = {{1, 2, 3, 4, 5},                     {5, 6, 7, 8, 6},                     {9, 5, 6, 8, 7},                     {2, 3, 5, 6, 8},                     {1, 2, 3, 4, 5}};            int convergingele, mid;            // If n is even, then convergence         // element will be null.         if (n % 2 == 0)          {             Console.Write("NULL\n");         }          else         {             // finding the mid             mid = n / 2;                // finding the converging element             convergingele = a[mid,mid];                Console.Write("{0}\n", convergingele);         }     } }    // This code is contributed by 29AjayKumar

Output:

6

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