Aquileo | C Program to Print Boundary Elements of a Matrix

Here, we will print the boundary elements of a matrix using a C program:

Approach:

Traverse the matrix from start to end.
Assign an outer loop to point to the row and the inner row to traverse the elements of the row.
if the element lies on the boundary (1st row, 1st column, last row, last column), then print the element, else print a blank space.

Example:

// C program to demonstrate the boundary
// element of matrix
#include <stdio.h>

// This function is display the Boundary of matrix
void printBoundary(int mat[][4], int m, int n)
{
    printf("\n Boundary of Matrix \n");
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            if (i == 0 || j == 0 || i == n - 1
                || j == n - 1)
                printf(" %d", mat[i][j]);
            else
                printf("  ");
        }
        printf("\n");
    }
}

// Driver code
int main()
{
    int mat[4][4] = { { 1, 2, 3, 4 },
                      { 1, 2, 3, 4 },
                      { 1, 2, 3, 4 },
                      { 1, 2, 3, 4 } };

    printf("\n Input Matrix \n");
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
            printf(" %d", mat[i][j]);
        }
        printf(" \n");
    }

    // printBoundary(a, 4, 4) function accepts a matrix, no
    // of rows and columns as input and display boundaries of
    // matrix
    printBoundary(mat, 4, 4);
    return 0;
}

Output

 Input Matrix 
 1 2 3 4 
 1 2 3 4 
 1 2 3 4 
 1 2 3 4 

 Boundary of Matrix 
 1 2 3 4
 1     4
 1     4
 1 2 3 4

Time Complexity: O(n*n), where n is the size of the array.

Space Complexity: O(1).

C Program to Print Boundary Elements of a Matrix

Approach:

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