Content-Length: 16859 | pFad | http://github.com/codebasics/data-structures-algorithms-python/pull/90.patch

thub.com From 001fd46c6160a13c73210d64eedf145a1b2bd047 Mon Sep 17 00:00:00 2001 From: rohansaxena2020 Date: Tue, 19 Mar 2024 23:46:16 -0400 Subject: [PATCH 1/5] Adding 1st exercise files --- 1.py | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ util.py | 9 +++++ 2 files changed, 114 insertions(+) create mode 100644 1.py create mode 100644 util.py diff --git a/1.py b/1.py new file mode 100644 index 0000000..860e313 --- /dev/null +++ b/1.py @@ -0,0 +1,105 @@ +# ### Binary Search Exercise +# 1. When I try to find number 5 in below list using binary search, it doesn't work and returns me -1 index. Why is that? + +# ```numbers = [1,4,6,9,10,5,7]``` + +# This is because the array is not sorted in order from lowest to highest. +# Once it splits the first time, it starts looking in the [1,4,6] range and doesn't find 5 + +# 1. Find index of all the occurances of a number from sorted list + +# ``` +# numbers = [1,4,6,9,11,15,15,15,17,21,34,34,56] +# number_to_find = 15 +# ``` +# This should return 5,6,7 as indices containing number 15 in the array + +from util import time_it + +@time_it +def linear_search(numbers_list, number_to_find): + for index, element in enumerate(numbers_list): + if element == number_to_find: + return index + return -1 + +@time_it +def binary_search(numbers_list, number_to_find): + left_index = 0 + right_index = len(numbers_list) - 1 + mid_index = 0 + + while left_index <= right_index: + mid_index = (left_index + right_index) // 2 + mid_number = numbers_list[mid_index] + + if mid_number == number_to_find: + return mid_index + + if mid_number < number_to_find: + left_index = mid_index + 1 + else: + right_index = mid_index - 1 + + return -1 + +def binary_search_recursive(numbers_list, number_to_find, left_index, right_index): + if right_index < left_index: + return -1 + + mid_index = (left_index + right_index) // 2 + if mid_index >= len(numbers_list) or mid_index < 0: + return -1 + + mid_number = numbers_list[mid_index] + + if mid_number == number_to_find: + return mid_index + + if mid_number < number_to_find: + left_index = mid_index + 1 + else: + right_index = mid_index - 1 + + return binary_search_recursive(numbers_list, number_to_find, left_index, right_index) + +#this should run the binary search, find the index, and then recursively run the search on both the right and left side +def binary_search_multiple(numbers_list, number_to_find): + + index = binary_search(numbers_list,number_to_find) + result_indices = [index] + + # find all indices on the left + i = index - 1 + while i>=0: + if numbers_list[i] == numbers_list[index]: + result_indices.append(i) + else: + break + i = i-1 + + # find all indices on the right + i = index + 1 + while i Date: Wed, 20 Mar 2024 22:53:31 -0400 Subject: [PATCH 2/5] adding 2nd exercise my solution --- 2.py | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 2.py diff --git a/2.py b/2.py new file mode 100644 index 0000000..a6e01ca --- /dev/null +++ b/2.py @@ -0,0 +1,84 @@ +# ### Bubble Sort Exercise + +# Modify [bubble_sort function](https://github.com/codebasics/data-structures-algorithms-python/blob/master/algorithms/2_BubbleSort/bubble_sort.py) such that it can sort following list of transactions happening in an electronic store, +# ``` +# elements = [ +# { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, +# { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, +# { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, +# { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, +# ] +# ``` +# bubble_sort function should take key from a transaction record and sort the list as per that key. For example, +# ``` +# bubble_sort(elements, key='transaction_amount') +# ``` +# This will sort elements by transaction_amount and your sorted list will look like, +# ``` +# elements = [ +# { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, +# { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, +# { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, +# { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, +# ] +# ``` +# But if you call it like this, +# ``` +# bubble_sort(elements, key='name') +# ``` +# output will be, +# ``` +# elements = [ +# { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, +# { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, +# { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, +# { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, +# ] +# ``` + +# base bubble_sort. you can use this to sort strings too +def bubble_sort(elements): + size = len(elements) + + for i in range(size-1): + swapped = False + for j in range(size-1-i): + if elements[j] > elements[j+1]: + tmp = elements[j] + elements[j] = elements[j+1] + elements[j+1] = tmp + swapped = True + + if not swapped: + break + +def bubble_sort_by_key(elements, key): + size = len(elements) + + for i in range(size-1): + swapped = False + for j in range(size-1-i): + if elements[j][key] > elements[j+1][key]: + tmp = elements[j] + elements[j] = elements[j+1] + elements[j+1] = tmp + swapped = True + + if not swapped: + break + + +elements = [5,9,2,1,67,34,88,34] +elements = [1,2,3,4,2] +elements = ["mona", "dhaval", "aamir", "tina", "chang"] + +bubble_sort(elements) +print(elements) + +elements2 = [ { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, + { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, + { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, + { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, + ] +bubble_sort_by_key(elements2,key='transaction_amount') +print(elements2) From da2f908e8a59d1ed955d4773ffe38b400e889248 Mon Sep 17 00:00:00 2001 From: rohansaxena2020 Date: Wed, 20 Mar 2024 22:57:20 -0400 Subject: [PATCH 3/5] updating 2nd exercise file --- 2.py | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/2.py b/2.py index a6e01ca..428b676 100644 --- a/2.py +++ b/2.py @@ -75,10 +75,10 @@ def bubble_sort_by_key(elements, key): bubble_sort(elements) print(elements) -elements2 = [ { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, +elementsv2 = [ { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, ] -bubble_sort_by_key(elements2,key='transaction_amount') -print(elements2) +bubble_sort_by_key(elementsv2,key='transaction_amount') +print(elementsv2) From 4784bacc2cf39618c44aeb1152f04c7288771d02 Mon Sep 17 00:00:00 2001 From: rohansaxena2020 Date: Wed, 20 Mar 2024 23:02:10 -0400 Subject: [PATCH 4/5] adding 1st exercise solution here --- 1.py | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ util.py | 9 +++++ 2 files changed, 114 insertions(+) create mode 100644 1.py create mode 100644 util.py diff --git a/1.py b/1.py new file mode 100644 index 0000000..860e313 --- /dev/null +++ b/1.py @@ -0,0 +1,105 @@ +# ### Binary Search Exercise +# 1. When I try to find number 5 in below list using binary search, it doesn't work and returns me -1 index. Why is that? + +# ```numbers = [1,4,6,9,10,5,7]``` + +# This is because the array is not sorted in order from lowest to highest. +# Once it splits the first time, it starts looking in the [1,4,6] range and doesn't find 5 + +# 1. Find index of all the occurances of a number from sorted list + +# ``` +# numbers = [1,4,6,9,11,15,15,15,17,21,34,34,56] +# number_to_find = 15 +# ``` +# This should return 5,6,7 as indices containing number 15 in the array + +from util import time_it + +@time_it +def linear_search(numbers_list, number_to_find): + for index, element in enumerate(numbers_list): + if element == number_to_find: + return index + return -1 + +@time_it +def binary_search(numbers_list, number_to_find): + left_index = 0 + right_index = len(numbers_list) - 1 + mid_index = 0 + + while left_index <= right_index: + mid_index = (left_index + right_index) // 2 + mid_number = numbers_list[mid_index] + + if mid_number == number_to_find: + return mid_index + + if mid_number < number_to_find: + left_index = mid_index + 1 + else: + right_index = mid_index - 1 + + return -1 + +def binary_search_recursive(numbers_list, number_to_find, left_index, right_index): + if right_index < left_index: + return -1 + + mid_index = (left_index + right_index) // 2 + if mid_index >= len(numbers_list) or mid_index < 0: + return -1 + + mid_number = numbers_list[mid_index] + + if mid_number == number_to_find: + return mid_index + + if mid_number < number_to_find: + left_index = mid_index + 1 + else: + right_index = mid_index - 1 + + return binary_search_recursive(numbers_list, number_to_find, left_index, right_index) + +#this should run the binary search, find the index, and then recursively run the search on both the right and left side +def binary_search_multiple(numbers_list, number_to_find): + + index = binary_search(numbers_list,number_to_find) + result_indices = [index] + + # find all indices on the left + i = index - 1 + while i>=0: + if numbers_list[i] == numbers_list[index]: + result_indices.append(i) + else: + break + i = i-1 + + # find all indices on the right + i = index + 1 + while i Date: Wed, 20 Mar 2024 23:08:46 -0400 Subject: [PATCH 5/5] adding 2nd exercise solution --- 2.py | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 2.py diff --git a/2.py b/2.py new file mode 100644 index 0000000..a6e01ca --- /dev/null +++ b/2.py @@ -0,0 +1,84 @@ +# ### Bubble Sort Exercise + +# Modify [bubble_sort function](https://github.com/codebasics/data-structures-algorithms-python/blob/master/algorithms/2_BubbleSort/bubble_sort.py) such that it can sort following list of transactions happening in an electronic store, +# ``` +# elements = [ +# { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, +# { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, +# { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, +# { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, +# ] +# ``` +# bubble_sort function should take key from a transaction record and sort the list as per that key. For example, +# ``` +# bubble_sort(elements, key='transaction_amount') +# ``` +# This will sort elements by transaction_amount and your sorted list will look like, +# ``` +# elements = [ +# { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, +# { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, +# { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, +# { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, +# ] +# ``` +# But if you call it like this, +# ``` +# bubble_sort(elements, key='name') +# ``` +# output will be, +# ``` +# elements = [ +# { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, +# { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, +# { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, +# { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, +# ] +# ``` + +# base bubble_sort. you can use this to sort strings too +def bubble_sort(elements): + size = len(elements) + + for i in range(size-1): + swapped = False + for j in range(size-1-i): + if elements[j] > elements[j+1]: + tmp = elements[j] + elements[j] = elements[j+1] + elements[j+1] = tmp + swapped = True + + if not swapped: + break + +def bubble_sort_by_key(elements, key): + size = len(elements) + + for i in range(size-1): + swapped = False + for j in range(size-1-i): + if elements[j][key] > elements[j+1][key]: + tmp = elements[j] + elements[j] = elements[j+1] + elements[j+1] = tmp + swapped = True + + if not swapped: + break + + +elements = [5,9,2,1,67,34,88,34] +elements = [1,2,3,4,2] +elements = ["mona", "dhaval", "aamir", "tina", "chang"] + +bubble_sort(elements) +print(elements) + +elements2 = [ { 'name': 'kathy', 'transaction_amount': 200, 'device': 'vivo'}, + { 'name': 'dhaval', 'transaction_amount': 400, 'device': 'google pixel'}, + { 'name': 'aamir', 'transaction_amount': 800, 'device': 'iphone-8'}, + { 'name': 'mona', 'transaction_amount': 1000, 'device': 'iphone-10'}, + ] +bubble_sort_by_key(elements2,key='transaction_amount') +print(elements2)

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