Define Array. Differentiate between 1D and 2D Array

Array is a collection of elements of the same data type stored in contiguous memory locations, accessed using a common name and an index.

Difference between 1D and 2D Array

Feature	1D Array	2D Array
Structure	Linear (single row)	Tabular (rows and columns)
Declaration	int a[5];	int a[3][4];
Access	Single index: a[i]	Two indices: a[i][j]
Memory	Total size = $n \times \text{sizeof(datatype)}$	Total size = $m \times n \times \text{sizeof(datatype)}$
Representation	Like a list	Like a matrix/table

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: Program to store 100 integers and display in ascending order

This program uses an array to store 100 integers and Bubble Sort algorithm to arrange them in ascending order before displaying.

#include <stdio.h>

int main() {
    int arr[100], i, j, temp;

    // Input 100 integers
    printf("Enter 100 integers:\n");
    for (i = 0; i < 100; i++) {
        scanf("%d", &arr[i]);
    }

    // Bubble Sort - Ascending Order
    for (i = 0; i < 99; i++) {
        for (j = 0; j < 99 - i; j++) {
            if (arr[j] > arr[j + 1]) {
                temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
        }
    }

    // Display sorted array
    printf("Array in ascending order:\n");
    for (i = 0; i < 100; i++) {
        printf("%d ", arr[i]);
    }

    return 0;
}

Explanation:

• Input phase: A for loop reads 100 integers from the user into the array.
• Sorting phase: Bubble Sort compares adjacent elements and swaps them if they are in the wrong order. The outer loop runs 99 times, and the inner loop reduces comparisons each pass.
• Output phase: The sorted array is printed in ascending order.

Conclusion: Bubble Sort has a time complexity of $O(n^2)$, which is simple to implement for sorting array elements in ascending order.