[19 Feb 2020] Program to print the Diagonals of a Matrix

Program to print the Diagonals of a Matrix
Given a 2D square matrix, print the Principal and Secondary diagonals.

Examples :

Input:
4
1 2 3 4
4 3 2 1
7 8 9 6
6 5 4 3
Output:
Principal Diagonal: 1, 3, 9, 3
Secondary Diagonal: 4, 3, 8, 6

Input:
3
1 1 1
1 1 1
1 1 1
Output:
Principal Diagonal: 1, 1, 1
Secondary Diagonal: 1, 1, 1

// C++ Program to print the Diagonals of a Matrix    #include <bits/stdc++.h> using namespace std;    const int MAX = 100;    // Function to print the Principal Diagonal void printPrincipalDiagonal(int mat[][MAX], int n) {     cout << "Principal Diagonal: ";        for (int i = 0; i < n; i++) {         for (int j = 0; j < n; j++) {                // Condition for principal diagonal             if (i == j)                 cout << mat[i][j] << ", ";         }     }     cout << endl; }    // Function to print the Secondary Diagonal void printSecondaryDiagonal(int mat[][MAX], int n) {     cout << "Secondary Diagonal: ";        for (int i = 0; i < n; i++) {         for (int j = 0; j < n; j++) {                // Condition for secondary diagonal             if ((i + j) == (n - 1))                 cout << mat[i][j] << ", ";         }     }     cout << endl; }    // Driver code int main() {     int n = 4;     int a[][MAX] = { { 1, 2, 3, 4 },                      { 5, 6, 7, 8 },                      { 1, 2, 3, 4 },                      { 5, 6, 7, 8 } };        printPrincipalDiagonal(a, n);     printSecondaryDiagonal(a, n);     return 0; }

Output:

Principal Diagonal: 1, 6, 3, 8, 
Secondary Diagonal: 4, 7, 2, 5,

// Java Program to print the Diagonals of a Matrix class GFG  {     static int MAX = 100;        // Function to print the Principal Diagonal     static void printPrincipalDiagonal(int mat[][], int n)     {         System.out.print("Principal Diagonal: ");            for (int i = 0; i < n; i++)         {             for (int j = 0; j < n; j++)              {                    // Condition for principal diagonal                 if (i == j)                 {                     System.out.print(mat[i][j] + ", ");                 }             }         }         System.out.println("");     }        // Function to print the Secondary Diagonal     static void printSecondaryDiagonal(int mat[][], int n)     {         System.out.print("Secondary Diagonal: ");            for (int i = 0; i < n; i++)          {             for (int j = 0; j < n; j++)              {                    // Condition for secondary diagonal                 if ((i + j) == (n - 1))                  {                     System.out.print(mat[i][j] + ", ");                 }             }         }         System.out.println("");     }        // Driver code     public static void main(String args[])     {         int n = 4;         int a[][] = {{1, 2, 3, 4},                      {5, 6, 7, 8},                      {1, 2, 3, 4},                      {5, 6, 7, 8}};            printPrincipalDiagonal(a, n);         printSecondaryDiagonal(a, n);     } }    // This code is contributed by Rajput-Ji

Output:

Principal Diagonal: 1, 6, 3, 8, 
Secondary Diagonal: 4, 7, 2, 5,

# Python3 Program to prthe Diagonals of a Matrix MAX = 100    # Function to prthe Principal Diagonal def printPrincipalDiagonal(mat, n):     print("Principal Diagonal: ", end = "")        for i in range(n):         for j in range(n):                # Condition for principal diagonal             if (i == j):                 print(mat[i][j], end = ", ")     print()    # Function to prthe Secondary Diagonal def printSecondaryDiagonal(mat, n):     print("Secondary Diagonal: ", end = "")        for i in range(n):         for j in range(n):                # Condition for secondary diagonal             if ((i + j) == (n - 1)):                 print(mat[i][j], end = ", ")     print()    # Driver code n = 4 a = [[ 1, 2, 3, 4 ],      [ 5, 6, 7, 8 ],      [ 1, 2, 3, 4 ],      [ 5, 6, 7, 8 ]]    printPrincipalDiagonal(a, n) printSecondaryDiagonal(a, n)    # This code is contributed by Mohit Kumar

Output:

Principal Diagonal: 1, 6, 3, 8, 
Secondary Diagonal: 4, 7, 2, 5,