Java Program for Selection Sort (original) (raw)

Last Updated : 23 Oct, 2024

The selection sort algorithm sorts an array by repeatedly finding the minimum element (considering ascending order) from the unsorted part and putting it at the beginning.

Algorithm for Selection Sort

Implementation of Selection Sort in Java is mentioned below:

**Step 1: Array arr with N size
**Step 2: Initialise i=0
**Step 3: If(i<N-1) Check for any element arr[j] where j>i and arr[j]<arr[i] then Swap arr[i] and arr[j]
**Step 4: i=i+1 and Goto Step 3
**Step 5: Exit

Program to Implement Selection Sort Java

Java `

// Java program for implementation // of Selection Sort

class SelectionSort { void sort(int a[]) { int n = a.length;

    // One by one move boundary of unsorted subarray
    for (int i = 0; i < n - 1; i++) {
      
        // Find the minimum element in unsorted array
        int min_idx = i;
      
        for (int j = i + 1; j < n; j++) {
            if (a[j] < a[min_idx])
                min_idx = j;
        }

        // Swap the found minimum element with the first
        // element
        int temp = a[min_idx];
        a[min_idx] = a[i];
        a[i] = temp;
    }
}

// main function
public static void main(String args[])
{
    SelectionSort ob = new SelectionSort();
    int a[] = { 64, 25, 12, 22, 11 };

    ob.sort(a);
      
      int n = a.length;
    for (int i = 0; i < n; ++i)
        System.out.print(a[i] + " ");

}

}

`

Complexity of the Above Method

**Time Complexity: O(n2)
**Auxiliary Space: O(1)

**Please refer complete article on **Selection Sort for more details!