insertion sort

insertion sort 

Insertion sort is a simple sorting algorithm that works the way we sort playing cards in our hands.


Time Complexity: O(n*2)
Auxiliary Space: O(1)
Boundary Cases: Insertion sort takes maximum time to sort if elements are sorted in reverse order. And it takes minimum time (Order of n) when elements are already sorted.
Algorithmic Paradigm: Incremental Approach
Sorting In Place: Yes
Stable: Yes
Online: Yes
Uses: Insertion sort is used when number of elements is small. It can also be useful when input array is almost sorted, only few elements are misplaced in complete big array.





https://www.geeksforgeeks.org/insertion-sort/

Notes: this code corresponds to the the picture example 



public void insertionSort(int[] array){
  int n = array.length;
  for(int i = 1; i < n; i++){
    int key = array[i];
    int j = i - 1;
    
    while(j >= 0 && array[j] > key){
      array[j + 1] = array[j];
      j = j - 1;
    }
    array[j + 1] = key;
  }
}






// why use only static , instead of also having public, private 

class InsertionSort{
  void insertionSort(int[] array){
    int n = array.length;
    for(int i = 1; i < n; i++){
      int key = array[i];
      int j = i - 1;
    
      while(j >= 0 && array[j] > key){
        array[j + 1] = array[j];
        j = j - 1;
      }
      array[j + 1] = key;
    }
  }
  
  // a utility function to print array of size n 
  static void printArray(int[] array){
    int n = array.length;
    for(int i = 0; i < n; i++){
      System.put.println();
    }
  }
  
  public static void main(String[] args){
    int[] array = {12, 11, 13, 5, 6};
    InsertionSort ob = new InsertionSort();
    ob.sort(array);
    
    printArray(array);
  }
}