insertion sort code user output code example

Example 1: java insertion sort

/**
* Insertion sort algorithm, O(n^2) time complexity.
*/
public static void insertionSort(int[] arr) {
  int n = arr.length;
  for(int i = 1; i < n; i++) {
    int key = arr[i];
    int j = i - 1;
    //shift until you find the position to place the element 'key'
    while(j >= 0 && arr[j] > key) {
      arr[j+1] = arr[j];
      j--;
    }
    //place element 'key' in the correct position in the sorted part of the array
    arr[j+1] = key;
  }
}

Example 2: program for insertion sort

# another method similar to insertion sort

def insertionSort(arr):
    for i in range(1, len(arr)):
        k = i
        for j in range(i-1, -1, -1):
            if arr[k] < arr[j]:  # if the key element is smaller than elements before it
                temp = arr[k]  # swapping the two numbers
                arr[k] = arr[j]
                arr[j] = temp

                k = j  # assigning the current index of key value to k
        

arr = [5, 2, 9, 1, 10, 19, 12, 11, 18, 13, 23, 20, 27, 28, 24, -2]

print("original array \n", arr)
insertionSort(arr)
print("\nSorted array \n", arr)