Create ternarySearch.py

Python/ternarySearch.py

@@ -0,0 +1,80 @@
+# Python3 program to illustrate 
+# recursive approach to ternary search 
+import math as mt 
+
+# Function to perform Ternary Search 
+def ternarySearch(l, r, key, ar): 
+
+	if (r >= l): 
+
+		# Find the mid1 and mid2 
+		mid1 = l + (r - l) //3
+		mid2 = r - (r - l) //3
+
+		# Check if key is present at any mid 
+		if (ar[mid1] == key): 
+			return mid1 
+
+		if (ar[mid2] == key): 
+			return mid2 
+
+		# Since key is not present at mid, 
+		# check in which region it is present 
+		# then repeat the Search operation 
+		# in that region 
+		if (key < ar[mid1]): 
+
+			# The key lies in between l and mid1 
+			return ternarySearch(l, mid1 - 1, key, ar) 
+
+		elif (key > ar[mid2]): 
+
+			# The key lies in between mid2 and r 
+			return ternarySearch(mid2 + 1, r, key, ar) 
+
+		else: 
+
+			# The key lies in between mid1 and mid2 
+			return ternarySearch(mid1 + 1, 
+								mid2 - 1, key, ar) 
+
+	# Key not found 
+	return -1
+
+# Driver code 
+l, r, p = 0, 9, 5
+
+# Get the array 
+# Sort the array if not sorted 
+ar = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ] 
+
+# Starting index 
+l = 0
+
+# length of array 
+r = 9
+
+# Checking for 5 
+
+# Key to be searched in the array 
+key = 5
+
+# Search the key using ternarySearch 
+p = ternarySearch(l, r, key, ar) 
+
+# Print the result 
+print("Index of", key, "is", p) 
+
+# Checking for 50 
+
+# Key to be searched in the array 
+key = 50
+
+# Search the key using ternarySearch 
+p = ternarySearch(l, r, key, ar) 
+
+# Print the result 
+print("Index of", key, "is", p) 
+
+# This code is contributed by 
+# Mohit kumar 29