Merge pull request #7 from santhon/improvements

Improvements

BubbleSort.py

@@ -1,26 +1,39 @@
+import sys
 
 
-array=[];
+def simple_bubble_sort(int_list):
-
+    count = len(int_list)
-# input
+    swapped = True
-print ("Enter any 6 Numbers for Unsorted Array : ");
+    while (swapped):
-for i in range(0, 6):
+        swapped = False
-	n=input();
+        for j in range(count - 1):
-	array.append(int(n));
+            if (int_list[j] > int_list[j + 1]):
-
+                int_list[j], int_list[j + 1] = int_list[j + 1], int_list[j]
-# Sorting
+                swapped = True
-print("")
+    return int_list
-for i in range(0, 6):
-	for j in range(0,5):
-		if (array[j]>array[j+1]):
-			temp=array[j];
-			array[j]=array[j+1];
-			array[j+1]=temp;
-
-# Output
-for i in range(0,6):
-	print(array[i]);
 
 
+def main():
+    # Python 2's `raw_input` has been renamed to `input` in Python 3
+    if sys.version_info.major < 3:
+        input_function = raw_input
+    else:
+        input_function = input
 
+    try:
+        print("Enter numbers separated by spaces:")
+        s = input_function()
+        inputs = list(map(int, s.split(' ')))
+        if len(inputs) < 2:
+            print('No Enough values to sort!')
+            raise Exception
 
+    except Exception as e:
+        print(e)
+    else:
+        sorted_input = simple_bubble_sort(inputs)
+        print('\nSorted list (min to max): {}'.format(sorted_input))
+
+if __name__ == '__main__':
+    print('==== Bubble Sort ====\n')
+    main()

InsertionSort.py

@@ -1,25 +1,40 @@
-array=[];
+import sys
-
-# input
-print ("Enter any 6 Numbers for Unsorted Array : ");
-for i in range(0, 6):
-	n=input();
-	array.append(int(n));
-
-# Sorting
-print("")
-for i in range(1, 6):
-	temp=array[i]
-	j=i-1;
-	while(j>=0 and temp<array[j]):
-		array[j+1]=array[j];
-		j-=1;
-	array[j+1]=temp;
-
-# Output
-for i in range(0,6):
-	print(array[i]);
 
 
+def simple_insertion_sort(int_list):
+    count = len(int_list)
+    for i in range(1, count):
+        temp = int_list[i]
+        j = i - 1
+        while(j >= 0 and temp < int_list[j]):
+            int_list[j + 1] = int_list[j]
+            j -= 1
+        int_list[j + 1] = temp
+
+    return int_list
 
 
+def main():
+    # Python 2's `raw_input` has been renamed to `input` in Python 3
+    if sys.version_info.major < 3:
+        input_function = raw_input
+    else:
+        input_function = input
+
+    try:
+        print("Enter numbers separated by spaces:")
+        s = input_function()
+        inputs = list(map(int, s.split(' ')))
+        if len(inputs) < 2:
+            print('No Enough values to sort!')
+            raise Exception
+
+    except Exception as e:
+        print(e)
+    else:
+        sorted_input = simple_insertion_sort(inputs)
+        print('\nSorted list (min to max): {}'.format(sorted_input))
+
+if __name__ == '__main__':
+    print('==== Insertion Sort ====\n')
+    main()

LinearSearch.py

@@ -1,21 +1,32 @@
-def sequentialSearch(alist, item):
+import sys
-		pos = 0
-		found = False
 
-		while pos < len(alist) and not found:
 
-			if alist[pos] == item:
+def sequential_search(alist, target):
-				found = True
+    for index, item in enumerate(alist):
-				print("Found")
+        if item == target:
+            print("Found target {} at index {}".format(target, index))
+            break
     else:
-				pos = pos+1
-		if found == False:
         print("Not found")
-		return found
 
-print("Enter numbers seprated by space")
-s = input()
-numbers = list(map(int, s.split()))
-trgt =int( input('enter a single number to be found in the list '))
-sequentialSearch(numbers, trgt)
 
+def main():
+    # Python 2's `raw_input` has been renamed to `input` in Python 3
+    if sys.version_info.major < 3:
+        input_function = raw_input
+    else:
+        input_function = input
+
+    try:
+        print("Enter numbers separated by spaces")
+        s = input_function()
+        inputs = list(map(int, s.split(' ')))
+        target = int(input_function('\nEnter a number to be found in list: '))
+    except Exception as e:
+        print(e)
+    else:
+        sequential_search(inputs, target)
+
+if __name__ == '__main__':
+    print('==== Linear Search ====\n')
+    main()

MergeSort.py

@@ -1,36 +1,59 @@
-def mergeSort(alist):
+import sys
-    print("Splitting ",alist)
+
-    if len(alist)>1:
+
-        mid = len(alist)//2
+def merge_sort(alist):
-        lefthalf = alist[:mid]
+    print("Splitting ", alist)
-        righthalf = alist[mid:]
+    if len(alist) > 1:
-        mergeSort(lefthalf)
+        mid = len(alist) // 2
-        mergeSort(righthalf)
+        left_half = alist[:mid]
-        i=0
+        right_half = alist[mid:]
-        j=0
+        merge_sort(left_half)
-        k=0
+        merge_sort(right_half)
-        while i < len(lefthalf) and j < len(righthalf):
+        i = j = k = 0
-            if lefthalf[i] < righthalf[j]:
+
-                alist[k]=lefthalf[i]
+        while i < len(left_half) and j < len(right_half):
-                i=i+1
+            if left_half[i] < right_half[j]:
+                alist[k] = left_half[i]
+                i += 1
             else:
-                alist[k]=righthalf[j]
+                alist[k] = right_half[j]
-                j=j+1
+                j += 1
-            k=k+1
+            k += 1
 
-        while i < len(lefthalf):
+        while i < len(left_half):
-            alist[k]=lefthalf[i]
+            alist[k] = left_half[i]
-            i=i+1
+            i += 1
-            k=k+1
+            k += 1
 
-        while j < len(righthalf):
+        while j < len(right_half):
-            alist[k]=righthalf[j]
+            alist[k] = right_half[j]
-            j=j+1
+            j += 1
-            k=k+1
+            k += 1
-    print("Merging ",alist)
+    print("Merging ", alist)
+    return alist
 
-print("Enter numbers seprated by space")
-s = input()
-numbers = list(map(int, s.split()))
-mergeSort(numbers)
 
+def main():
+    # Python 2's `raw_input` has been renamed to `input` in Python 3
+    if sys.version_info.major < 3:
+        input_function = raw_input
+    else:
+        input_function = input
+
+    try:
+        print("Enter numbers separated by spaces:")
+        s = input_function()
+        inputs = list(map(int, s.split(' ')))
+        if len(inputs) < 2:
+            print('No Enough values to sort!')
+            raise Exception
+
+    except Exception as e:
+        print(e)
+    else:
+        sorted_input = merge_sort(inputs)
+        print('\nSorted list (min to max): {}'.format(sorted_input))
+
+if __name__ == '__main__':
+    print('==== Merge Sort ====\n')
+    main()

QuickSort.py

@@ -1,31 +1,41 @@
+import sys
 
-def quicksort(A, p, r):
+
+def quick_sort(A, p, r):
     if p < r:
         q = partition(A, p, r)
-        quicksort(A, p, q - 1)
+        quick_sort(A, p, q - 1)
-        quicksort(A, q + 1, r)
+        quick_sort(A, q + 1, r)
+    return A
 
 
 def partition(A, p, r):
-    x = A[r]
     i = p - 1
     for j in range(p, r):
-        if A[j] <= x:
+        if A[j] <= A[r]:
             i += 1
-            tmp = A[i]
+            A[i], A[j] = A[j], A[i]
-            A[i] = A[j]
+    A[i + 1], A[r] = A[r], A[i + 1]
-            A[j] = tmp
-    tmp = A[i+1]
-    A[i+1] = A[r]
-    A[r] = tmp
     return i + 1
 
 
-if __name__ == "__main__":
+def main():
-    print('Enter values seperated by space:')
+    # Python 2's `raw_input` has been renamed to `input` in Python 3
-    A = [int (item) for item in input().split(' ')]
+    if sys.version_info.major < 3:
-    # A = [23, 45, 43, 12, 67, 98, 123, 99]
+        input_function = raw_input
-    # partition(A, 0, 7)
+    else:
-    print(A)
+        input_function = input
-    quicksort(A, 0, 7)
+
-    print(A)
+    try:
+        print("Enter numbers separated by spaces")
+        s = input_function()
+        inputs = list(map(int, s.split(' ')))
+    except Exception as e:
+        print(e)
+    else:
+        sorted_input = quick_sort(inputs, 0, len(inputs) - 1)
+        print('\nSorted list (min to max): {}'.format(sorted_input))
+
+if __name__ == '__main__':
+    print('==== Quick Sort ====\n')
+    main()

README.md

@@ -1,2 +1,89 @@
-# Python-
+# The Algorithms - Python
-All Algorithms implemented in Python
+
+### All algorithms implemented in Python (for education)
+
+These are for demonstration purposes only. There are many implementations of sorts in the Python standard library that are much better for performance reasons.
+
+## Sorting Algorithms
+
+### Binary
+Add comments here
+
+### Bubble
+![alt text][bubble-image]
+
+From [Wikipedia][bubble-wiki]: Bubble sort, sometimes referred to as sinking sort, is a simple sorting algorithm that repeatedly steps through the list to be sorted, compares each pair of adjacent items and swaps them if they are in the wrong order. The pass through the list is repeated until no swaps are needed, which indicates that the list is sorted.
+
+__Properties__
+* Worst case performance	O(n^2)
+* Best case performance	O(n)
+* Average case performance	O(n^2)
+
+###### View the algorithm in [action][bubble-toptal]
+
+
+
+### Insertion
+![alt text][insertion-image]
+
+From [Wikipedia][insertion-wiki]: Insertion sort is a simple sorting algorithm that builds the final sorted array (or list) one item at a time. It is much less efficient on large lists than more advanced algorithms such as quicksort, heapsort, or merge sort.
+
+__Properties__
+* Worst case performance	O(n^2)
+* Best case performance	O(n)
+* Average case performance	O(n^2)
+
+###### View the algorithm in [action][insertion-toptal]
+
+
+## Merge
+![alt text][merge-image]
+
+From [Wikipedia][merge-wiki]: In computer science, merge sort (also commonly spelled mergesort) is an efficient, general-purpose, comparison-based sorting algorithm. Most implementations produce a stable sort, which means that the implementation preserves the input order of equal elements in the sorted output. Mergesort is a divide and conquer algorithm that was invented by John von Neumann in 1945.
+
+__Properties__
+* Worst case performance	O(n log n)
+* Best case performance	O(n)
+* Average case performance	O(n)
+
+
+###### View the algorithm in [action][merge-toptal]
+
+## Quick
+![alt text][quick-image]
+
+From [Wikipedia][quick-wiki]: Quicksort (sometimes called partition-exchange sort) is an efficient sorting algorithm, serving as a systematic method for placing the elements of an array in order.
+
+__Properties__
+* Worst case performance	O(n^2)
+* Best case performance	O(n log n) or O(n) with three-way partition
+* Average case performance	O(n^2)
+
+###### View the algorithm in [action][quick-toptal]
+
+
+## Search Algorithms
+
+### Linear
+Add comments here
+
+## Ciphers
+
+### Caesar
+Add comments here
+
+[bubble-toptal]: https://www.toptal.com/developers/sorting-algorithms/bubble-sort
+[bubble-wiki]: https://en.wikipedia.org/wiki/Bubble_sort
+[bubble-image]: https://upload.wikimedia.org/wikipedia/commons/thumb/8/83/Bubblesort-edited-color.svg/220px-Bubblesort-edited-color.svg.png "Bubble Sort"
+
+[insertion-toptal]: https://www.toptal.com/developers/sorting-algorithms/insertion-sort
+[insertion-wiki]: https://en.wikipedia.org/wiki/Insertion_sort
+[insertion-image]: https://upload.wikimedia.org/wikipedia/commons/7/7e/Insertionsort-edited.png "Insertion Sort"
+
+[quick-toptal]: https://www.toptal.com/developers/sorting-algorithms/quick-sort
+[quick-wiki]: https://en.wikipedia.org/wiki/Quicksort
+[quick-image]: https://upload.wikimedia.org/wikipedia/commons/6/6a/Sorting_quicksort_anim.gif "Quick Sort"
+
+[merge-toptal]: https://www.toptal.com/developers/sorting-algorithms/merge-sort
+[merge-wiki]: https://en.wikipedia.org/wiki/Merge_sort
+[merge-image]: https://upload.wikimedia.org/wikipedia/commons/c/cc/Merge-sort-example-300px.gif "Merge Sort"