How to implement bubble sort in a shell script?

Implementing Bubble Sort in a Shell Script

Bubble sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements, and swaps them if they are in the wrong order. The algorithm gets its name from the way smaller or larger elements "bubble" to the top of the list.

To implement bubble sort in a shell script, we can follow these steps:

1. Define a function to perform the bubble sort.
2. Iterate through the array and compare adjacent elements.
3. Swap the elements if they are in the wrong order.
4. Repeat the process until the entire array is sorted.

Here's an example implementation in a shell script:

#!/bin/bash

# Function to perform bubble sort
bubble_sort() {
    local arr=("$@")
    local n=${#arr[@]}

    for ((i = 0; i < n - 1; i++)); do
        for ((j = 0; j < n - i - 1; j++)); do
            if [[ ${arr[j]} -gt ${arr[j + 1]} ]]; then
                # Swap elements
                local temp=${arr[j]}
                arr[j]=${arr[j + 1]}
                arr[j + 1]=$temp
            fi
        done
    done

    echo "${arr[@]}"
}

# Example usage
numbers=(5 2 8 1 9)
echo "Original array: ${numbers[@]}"
bubble_sort "${numbers[@]}"
echo "Sorted array: ${numbers[@]}"

In this example, the bubble_sort function takes an array as input and performs the bubble sort algorithm. The outer loop iterates through the array, and the inner loop compares adjacent elements, swapping them if they are in the wrong order. The process is repeated until the entire array is sorted.

Here's a Mermaid diagram that visualizes the bubble sort algorithm:

The bubble sort algorithm is simple to understand and implement, but it has a time complexity of O(n^2), which means it is not very efficient for large datasets. However, it can be a good choice for small arrays or as a learning exercise for beginners in shell scripting.