1. Sorting Example Insertion Sort

2. Insertion Sort Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n In each iteration i  Move item i left-to-right if needed. n Exchange next element with larger elements to its left, one-by-one.

3. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

4. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

5. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

6. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

7. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

8. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

9. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

10. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

11. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

12. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

13. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

14. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

15. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

16. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

17. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

18. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

19. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

20. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

21. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

22. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

23. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

24. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

25. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

26. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

27. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

28. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

29. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

30. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

31. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

32. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

33. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

34. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

35. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

36. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

37. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

38. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

39. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

40. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

41. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

42. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

43. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

44. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

45. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

46. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

47. Insertion Sort Demo Sorting problem: n Given an array of N integers, rearrange them so that they are in increasing order. Insertion sort n Brute-force sorting solution. n Move left-to-right through array. n Exchange next element with larger elements to its left, one-by-one.

48. An insertion sort partitions the array into two regions Insertion Sort

49. Insertion Sort Algorithm public void insertionSort(Comparable[] arr) { for (int i = 1; i < arr.length; ++i) { Comparable temp = arr[i]; int pos = i; // Shuffle up all sorted items > arr[i] while (pos > 0 && arr[pos-1].compareTo(temp) > 0) { arr[pos] = arr[pos–1]; pos--; } // end while // Insert the current item arr[pos] = temp; }

50. public void insertionSort(Comparable[] arr) { for (int i = 1; i < arr.length; ++i) { Comparable temp = arr[i]; int pos = i; // Shuffle up all sorted items > arr[i] while (pos > 0 && arr[pos-1].compareTo(temp) > 0) { arr[pos] = arr[pos–1]; pos--; } // end while // Insert the current item arr[pos] = temp; } Insertion Sort Analysis outer loopouter times inner loop inner times

51. Insertion Sort Analysis Best Case: Input array is already sorted In each iteration, we do one comparison. Total : N-1 comparisons Worst Case: Input array is sorted in reverse order In each iteration i, we do i comparisons. Total : N(N-1) comparisons

52. Insertion Sort: Cost Function 1 operation to initialize the outer loop The outer loop is evaluated n-1 times n 5 instructions (including outer loop comparison and increment) n Total cost of the outer loop: 5(n-1) How many times the inner loop is evaluated is affected by the state of the array to be sorted Best case: the array is already completely sorted so no “shifting” of array elements is required. n We only test the condition of the inner loop once (2 operations = 1 comparison + 1 element comparison), and the body is never executed n Requires 2(n-1) operations.

53. Insertion Sort: Cost Function Worst case: the array is sorted in reverse order (so each item has to be moved to the front of the array) n In the i-th iteration of the outer loop, the inner loop will perform 4i+1 operations n Therefore, the total cost of the inner loop will be 2n(n-1)+n-1 Time cost: Best case: 7(n-1)  Linear Worst case: 5(n-1) + 2n(n-1) + (n-1)  Quadratic