|
| 1 | +import random |
| 2 | +import time |
| 3 | +# sorting algorithms |
| 4 | + |
| 5 | +def bubble_sort(arr): |
| 6 | + n = len(arr) |
| 7 | + for i in range(n): |
| 8 | + for j in range(0, n-i-1): |
| 9 | + if arr[j] > arr[j+1] : |
| 10 | + arr[j], arr[j+1] = arr[j+1], arr[j] |
| 11 | + |
| 12 | +def insertion_sort(arr): |
| 13 | + count = 0 |
| 14 | + for i in range(1, len(arr)): |
| 15 | + key = arr[i] |
| 16 | + j = i-1 |
| 17 | + while j >= 0 and key < arr[j] : |
| 18 | + arr[j + 1] = arr[j] |
| 19 | + j -= 1 |
| 20 | + arr[j + 1] = key |
| 21 | + |
| 22 | + count+=1 |
| 23 | + |
| 24 | +def selection_sort(arr): |
| 25 | + for i in range(len(arr)): |
| 26 | + min_idx = i |
| 27 | + for j in range(i+1, len(arr)): |
| 28 | + if arr[min_idx] > arr[j]: |
| 29 | + min_idx = j |
| 30 | + arr[i],arr[min_idx] = arr[min_idx], arr[i] |
| 31 | + |
| 32 | +def quick_sort(arr,low,high): |
| 33 | + |
| 34 | + if len(arr) == 1: |
| 35 | + return arr |
| 36 | + if low < high: |
| 37 | + i = (low-1) |
| 38 | + pivot = arr[high] |
| 39 | + for j in range(low, high): |
| 40 | + if arr[j] <= pivot: |
| 41 | + i = i+1 |
| 42 | + arr[i], arr[j] = arr[j], arr[i] |
| 43 | + arr[i+1], arr[high] = arr[high], arr[i+1] |
| 44 | + pi=(i+1) |
| 45 | + quick_sort(arr, low, pi-1) |
| 46 | + quick_sort(arr, pi+1, high) |
| 47 | + |
| 48 | + |
| 49 | +# serching algorithms |
| 50 | +def linear_search(arr): |
| 51 | + itemPos = 0 |
| 52 | + itemFound = False |
| 53 | + while itemPos < len(array) and itemFound == False: |
| 54 | + if arr[itemPos] == itemWanted: |
| 55 | + itemFound = True |
| 56 | + else: |
| 57 | + itemPos +=1 |
| 58 | + if itemFound == True: |
| 59 | + print("item at index ", itemPos) |
| 60 | + else: |
| 61 | + print("item not in list") |
| 62 | + |
| 63 | + |
| 64 | +def binary_search(arr, low, high): |
| 65 | + if high >= low: |
| 66 | + |
| 67 | + mid = (high + low) // 2 |
| 68 | + if arr[mid] == itemWanted: |
| 69 | + print("item at index ", mid) |
| 70 | + |
| 71 | + elif arr[mid] > itemWanted: |
| 72 | + return binary_search(arr, low, mid-1) |
| 73 | + |
| 74 | + else: |
| 75 | + return binary_search(arr, mid + 1, high) |
| 76 | + |
| 77 | + else: |
| 78 | + print("item not in list") |
| 79 | + |
| 80 | + |
| 81 | +if __name__ == "__main__": |
| 82 | + array = [] |
| 83 | + |
| 84 | + itemWanted = 10 |
| 85 | + length_of_list = 100000 |
| 86 | + |
| 87 | + # fills an array with random numbers from range specified |
| 88 | + for x in range(length_of_list): |
| 89 | + array.append(random.randint(0,length_of_list)) |
| 90 | + start_time = time.time() |
| 91 | + # sorting algorithm |
| 92 | + |
| 93 | + quick_sort(array,0,len(array)-1) |
| 94 | + |
| 95 | + past_time=time.time() - start_time |
| 96 | + |
| 97 | + print("--- %s seconds to sort ---" % (time.time() - start_time)) |
| 98 | + # searching algorithm |
| 99 | + binary_search(array,0,len(array)-1) |
| 100 | + |
| 101 | + print("--- %s seconds to find ---" % ((time.time() - start_time) - past_time)) |
| 102 | + |
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