C Program to Sort an Array in Ascending Order

Introduction

Sorting an array in ascending order involves arranging the elements of the array so that each element is less than or equal to the next element. This guide will show you how to write a C program that sorts an array in ascending order.

Problem Statement

Create a C program that:

• Takes the size of the array as input from the user.
• Takes the elements of the array as input.
• Sorts the array in ascending order.
• Displays the sorted array.

Example:

• Input: Array = [5, 2, 9, 1, 5, 6]
• Output: Sorted Array = [1, 2, 5, 5, 6, 9]

Solution Steps

1. Include the Standard Input-Output Library: Use #include <stdio.h> to include the standard input-output library, which is necessary for using printf and scanf functions.
2. Write the Main Function: Define the main function, which is the entry point of every C program.
3. Declare Variables: Declare variables to store the array size, the array elements, and temporary variables for swapping.
4. Input the Array Size: Use scanf to take input from the user for the size of the array.
5. Input the Array Elements: Use a loop to take input from the user for the elements of the array.
6. Sort the Array in Ascending Order: Use the Bubble Sort algorithm to sort the array in ascending order.
7. Display the Sorted Array: Use printf to display the sorted array.

C Program

#include <stdio.h>

int main() {
    // Step 1: Declare variables to hold the array size, elements, and a temporary variable for swapping
    int n, temp;

    // Step 2: Prompt the user to enter the size of the array
    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    // Step 3: Declare an array to hold the elements
    int arr[n];

    // Step 4: Input the array elements
    printf("Enter %d elements:\n", n);
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    // Step 5: Sort the array in ascending order using Bubble Sort
    for (int i = 0; i < n-1; i++) {
        for (int j = 0; j < n-i-1; j++) {
            if (arr[j] > arr[j+1]) {
                // Swap the elements
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
    }

    // Step 6: Display the sorted array
    printf("Sorted array in ascending order: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");

    return 0;  // Step 7: Return 0 to indicate successful execution
}

Explanation

Step 1: Declare Variables

• The variable n is declared to store the size of the array. temp is used as a temporary variable for swapping elements during sorting.

Step 2: Input the Array Size

• The program prompts the user to enter the size of the array using printf. The scanf function then reads the input and stores it in the variable n.

Step 3: Declare the Array

• The program declares an array arr of size n to hold the elements provided by the user.

Step 4: Input the Array Elements

• The program uses a for loop to take input for each element of the array. The loop iterates from 0 to n-1, reading the elements using scanf.

Step 5: Sort the Array in Ascending Order

• The program uses the Bubble Sort algorithm to sort the array in ascending order:
  • The outer loop iterates through the entire array n-1 times.
  • The inner loop compares each element with its adjacent element and swaps them if they are in the wrong order. The smallest element "bubbles" up to its correct position at the beginning of each pass.

Step 6: Display the Sorted Array

• After the sorting process is complete, the program displays the sorted array using a for loop and the printf function.

Step 7: Return 0

• The return 0; statement indicates that the program executed successfully.

Output Example

Example:

Enter the number of elements in the array: 5
Enter 5 elements:
64
25
12
22
11
Sorted array in ascending order: 11 12 22 25 64

Another Example:

Enter the number of elements in the array: 4
Enter 4 elements:
9
1
4
7
Sorted array in ascending order: 1 4 7 9

Conclusion

This C program demonstrates how to sort an array in ascending order using the Bubble Sort algorithm. It covers basic concepts such as arrays, loops, and sorting algorithms, making it a useful example for beginners learning C programming.