Done precourse2

Exercise_1.py

@@ -1,22 +1,40 @@
+""""
+// Time Complexity :O( log n)
+// Space Complexity :O(1)
+// Did this code successfully run on Leetcode :
+// Any problem you faced while coding this :
+
+
+// Your code here along with comments explaining your approach
+
+
+"""
+
+
 # Python code to implement iterative Binary  
 # Search. 
 
 # It returns location of x in given array arr  
 # if present, else returns -1 
 def binarySearch(arr, l, r, x): 
-
-  #write your code here
-
-
-
+    while l <= r:
+        mid = l + (r - l) // 2  # Avoids overflow compared to (l + r) // 2
+        if arr[mid] == x:
+            return mid
+        elif arr[mid] < x:
+            l = mid + 1
+        else:
+            r = mid - 1
+    return -1
+
 # Test array 
-arr = [ 2, 3, 4, 10, 40 ] 
+arr = [2, 3, 4, 10, 40] 
 x = 10
-  
+
 # Function call 
 result = binarySearch(arr, 0, len(arr)-1, x) 
-  
+
 if result != -1: 
-    print "Element is present at index % d" % result 
+    print("Element is present at index %d" % result) 
 else: 
-    print "Element is not present in array"
+    print("Element is not present in array")

Exercise_2.py

@@ -1,14 +1,29 @@
+
 # Python program for implementation of Quicksort Sort 
 
 # give you explanation for the approach
 def partition(arr,low,high):
+    pivot = arr[high]  # Last element as pivot
+    i = low - 1         # Index of smaller element
+
+    for j in range(low, high):
+        if arr[j] <= pivot:
+            i += 1
+            arr[i], arr[j] = arr[j], arr[i]  # Swap
+
+    arr[i + 1], arr[high] = arr[high], arr[i + 1]  # Place pivot in the middle
+    return i + 1
 
 
     #write your code here
 
 
 # Function to do Quick sort 
-def quickSort(arr,low,high): 
+def quickSort(arr,low,high):
+    if low < high:
+        pi = partition(arr, low, high)
+        quickSort(arr, low, pi - 1)
+        quickSort(arr, pi + 1, high) 
 
     #write your code here