Example: Display Upper Triangular Matrix in C

// Display Upper Triangular Matrix
#include <stdio.h>

int main() {
    int matrix[3][3] = {
        {1, 2, 3},
        {4, 5, 6},
        {7, 8, 9}
    };
    int rows = 3;
    int cols = 3;

    printf("Original Matrix:\n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }

    printf("\nUpper Triangular Matrix:\n");
    for (int i = 0; i < rows; i++) { // Iterate through rows
        for (int j = 0; j < cols; j++) { // Iterate through columns
            // Step 1: Check if the current element is on or above the main diagonal
            // The main diagonal is where i == j. Elements above have i < j.
            if (i <= j) {
                printf("%d ", matrix[i][j]); // Step 2: Print the element
            } else {
                printf("0 "); // Step 3: Print 0 for elements below the main diagonal
            }
        }
        printf("\n"); // Move to the next line after each row
    }

    return 0;
}