Added Quicksort

divide_and_conquer/quick_sort.py

@@ -0,0 +1,40 @@
+# Implementation of Quick sort algo-> https://en.wikipedia.org/wiki/Quicksort
+class QuickSort():
+    def __init__(self, array,asc=True)->None:
+        self.asc=asc
+        self.array = array
+
+    def partition(self, start, end)->integer:  # Will sort in ascending order by default
+        '''Normal partition routine read more about it here: google Lomuto partition algorithm. '''
+        i = start
+        j = start+1
+        while(j < end):
+            if(self.asc):
+                if(self.array[j] < self.array[start]):
+                    i += 1
+                    self.array[j], self.array[i] = self.array[i], self.array[j]
+                j += 1
+            else:
+                if(self.array[j] > self.array[start]):
+                    i += 1
+                    self.array[j], self.array[i] = self.array[i], self.array[j]
+                j += 1
+        self.array[start], self.array[i] = self.array[i], self.array[start]
+        return i
+    def sort(self,start,end)->None: #recursive implementation of quick sort
+        if(start>=end):
+            return
+        i=self.partition(start,end)
+        self.sort(start,i)
+        self.sort(i+1,end)
+
+
+ls = [3, 2, 1, 4, 3, 0, 5, 9,0,99,88,77,66,55,1]
+#sort in ascending order
+q_s=QuickSort(ls)
+q_s.sort(start=0,end=len(ls))
+print(ls)
+#descending
+q_s=QuickSort(ls,False)
+q_s.sort(start=0,end=len(ls))
+print(ls)