Merge pull request geekcomputers#167 from ebiwari/factorial

Computation for Factorial Permutation and Combination

Author: geekcomputers

factorial_perm_comp.py

@@ -0,0 +1,79 @@
+# Script Name		: factorial_perm_comp.py
+# Author			: Ebiwari Williams
+# Created			: 20th May 2017
+# Last Modified		: 
+# Version			: 1.0
+
+# Modifications		: 
+
+# Description		: Find Factorial, Permutation and Combination of a Number
+
+
+def factorial(n):	
+	fact = 1
+	while(n >= 1 ): 
+		fact = fact * n 
+		n = n - 1
+
+	return fact
+
+
+def permutation(n,r):
+	return factorial(n)/factorial(n-r)
+
+
+
+def combination(n,r):
+	return permutation(n,r)/factorial(r)
+
+
+def main():
+	print('choose between operator 1,2,3')
+	print('1) Factorial')
+	print('2) Permutation')
+	print('3) Combination')
+
+	operation = input('\n')
+
+	if(operation ==  '1'):
+		print('Factorial Computation\n')
+		while(True):
+			try:
+				n = int(input('\n Enter  Value for n '))
+				print('Factorial of {} = {}'.format(n,factorial(n)))
+				break
+			except(ValueError):
+				print('Invalid Value')
+				continue
+
+	elif(operation == '2'):
+		print('Permutation Computation\n')
+
+		while(True):
+			try:
+				n  = int(input('\n Enter Value for n '))
+				r  = int(input('\n Enter Value for r '))
+				print('Permutation of {}P{} = {}'.format(n,r,permutation(n,r)))
+				break
+			except(ValueError):
+				print('Invalid Value')
+				continue
+
+
+	elif(operation == '3'):
+		print('Combination Computation\n')
+		while(True):
+			try:
+				n  = int(input('\n Enter Value for n '))
+				r  = int(input('\n Enter Value for r '))
+
+				print('Combination of {}C{} = {}'.format(n,r,combination(n,r)))
+				break
+
+			except(ValueError):
+				print('Invalid Value')
+				continue
+
+
+if __name__ == '__main__':
+	main()