Sorting • Sorting takes an unordered collection and makes it an ordered one. 5 12 35 42 77 101 1 2 3 4 5 6 5 12 35 42 77 101 1 2 3 4 5 6
Exchange/Bubble Sort: It uses simple algorithm. It sorts by comparing each pair of adjacent items and swapping them in the order. This will be repeated until no swaps are needed. The algorithm got its name from the way smaller elements "bubble" to the top of the list. It is not that much efficient, when a list is having more than a few elements. Among simple sorting algorithms, algorithms like insertion sort are usually considered as more efficient. Bubble sort is little slower compared to other sorting techniques but it is easy because it deals with only two elements at a time.
"Bubbling Up" the Largest Element • Traverse a collection of elements – Move from the front to the end – “Bubble” the largest value to the end using pair-wise comparisons and swapping 5 12 35 42 77 101 1 2 3 4 5 6
"Bubbling Up" the Largest Element 5 12 35 42 77 101 1 2 3 4 5 6 Swap 42 77
"Bubbling Up" the Largest Element 5 77 12 35 42 101 1 2 3 4 5 6 No need to swap
Bubble Sort 1. In each pass, we compare adjacent elements and swap them if they are out of order until the end of the list. By doing so, the 1st pass ends up “bubbling up” the largest element to the last position on the list 2. The 2nd pass bubbles up the 2nd largest, and so on until, after N-1 passes, the list is sorted. Example: Pass 1 89 | 45 68 90 29 34 17 Pass 2 45 | 68 89 29 34 17 45 89 | 68 90 29 34 17 45 68 | 89 29 34 17 68 89 | 90 29 34 17 68 89 | 29 34 17 89 90 | 29 34 17 29 89 | 34 17 29 90 | 34 17 34 89 | 17 34 90 | 17 17 89 17 90 45 68 89 29 34 17 90 45 68 29 34 17 89 largest 2nd largest
Items of Interest • Notice that only the largest value is correctly placed • All other values are still out of order • So we need to repeat this process 77 12 35 42 5 1 2 3 4 5 6 101 Largest value correctly placed
// Optimized java implementation of Bubble sort import java.io.*; class GFG { // An optimized version of Bubble Sort static void bubbleSort(int arr[], int n) { int i, j, temp; boolean swapped; for (i = 0; i < n - 1; i++) { swapped = false; for (j = 0; j < n - i - 1; j++) { if (arr[j] > arr[j + 1]) { // Swap arr[j] and arr[j+1] temp = arr[j]; arr[j] = arr[j + 1]; arr[j + 1] = temp; swapped = true; } } // If no two elements were // swapped by inner loop, then break if (swapped == false) break; } } // Function to print an array static void printArray(int arr[], int size) { int i; for (i = 0; i < size; i++) System.out.print(arr[i] + " "); System.out.println(); } // Driver program public static void main(String args[]) { int arr[] = { 64, 34, 25, 12, 22, 11, 90 }; int n = arr.length; bubbleSort(arr, n); System.out.println("Sorted array: "); printArray(arr, n); } }
Summary • “Bubble Up” algorithm will move largest value to its correct location (to the right) • Repeat “Bubble Up” until all elements are correctly placed: – Maximum of N-1 times • We reduce the number of elements we compare each time one is correctly placed
Thank You

MYSQL DATABASE MYSQL DATABASE MYSQL DATABASE BUBLESORT.pptx

  • 2.
    Sorting • Sorting takesan unordered collection and makes it an ordered one. 5 12 35 42 77 101 1 2 3 4 5 6 5 12 35 42 77 101 1 2 3 4 5 6
  • 3.
    Exchange/Bubble Sort: It usessimple algorithm. It sorts by comparing each pair of adjacent items and swapping them in the order. This will be repeated until no swaps are needed. The algorithm got its name from the way smaller elements "bubble" to the top of the list. It is not that much efficient, when a list is having more than a few elements. Among simple sorting algorithms, algorithms like insertion sort are usually considered as more efficient. Bubble sort is little slower compared to other sorting techniques but it is easy because it deals with only two elements at a time.
  • 4.
    "Bubbling Up" theLargest Element • Traverse a collection of elements – Move from the front to the end – “Bubble” the largest value to the end using pair-wise comparisons and swapping 5 12 35 42 77 101 1 2 3 4 5 6
  • 5.
    "Bubbling Up" theLargest Element 5 12 35 42 77 101 1 2 3 4 5 6 Swap 42 77
  • 6.
    "Bubbling Up" theLargest Element 5 77 12 35 42 101 1 2 3 4 5 6 No need to swap
  • 7.
    Bubble Sort 1. Ineach pass, we compare adjacent elements and swap them if they are out of order until the end of the list. By doing so, the 1st pass ends up “bubbling up” the largest element to the last position on the list 2. The 2nd pass bubbles up the 2nd largest, and so on until, after N-1 passes, the list is sorted. Example: Pass 1 89 | 45 68 90 29 34 17 Pass 2 45 | 68 89 29 34 17 45 89 | 68 90 29 34 17 45 68 | 89 29 34 17 68 89 | 90 29 34 17 68 89 | 29 34 17 89 90 | 29 34 17 29 89 | 34 17 29 90 | 34 17 34 89 | 17 34 90 | 17 17 89 17 90 45 68 89 29 34 17 90 45 68 29 34 17 89 largest 2nd largest
  • 8.
    Items of Interest •Notice that only the largest value is correctly placed • All other values are still out of order • So we need to repeat this process 77 12 35 42 5 1 2 3 4 5 6 101 Largest value correctly placed
  • 9.
    // Optimized javaimplementation of Bubble sort import java.io.*; class GFG { // An optimized version of Bubble Sort static void bubbleSort(int arr[], int n) { int i, j, temp; boolean swapped; for (i = 0; i < n - 1; i++) { swapped = false; for (j = 0; j < n - i - 1; j++) { if (arr[j] > arr[j + 1]) { // Swap arr[j] and arr[j+1] temp = arr[j]; arr[j] = arr[j + 1]; arr[j + 1] = temp; swapped = true; } } // If no two elements were // swapped by inner loop, then break if (swapped == false) break; } } // Function to print an array static void printArray(int arr[], int size) { int i; for (i = 0; i < size; i++) System.out.print(arr[i] + " "); System.out.println(); } // Driver program public static void main(String args[]) { int arr[] = { 64, 34, 25, 12, 22, 11, 90 }; int n = arr.length; bubbleSort(arr, n); System.out.println("Sorted array: "); printArray(arr, n); } }
  • 10.
    Summary • “Bubble Up”algorithm will move largest value to its correct location (to the right) • Repeat “Bubble Up” until all elements are correctly placed: – Maximum of N-1 times • We reduce the number of elements we compare each time one is correctly placed
  • 11.