Computation for Factorial Permutation and Combination

Author: ebiwari

factorial_perm_comp.py

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+# 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
+
+
+deffactorial(n): 
+fact=1
+while(n>=1 ): 
+fact=fact*n
+n=n-1
+
+returnfact
+
+
+defpermutation(n,r):
+returnfactorial(n)/factorial(n-r)
+
+
+
+defcombination(n,r):
+returnpermutation(n,r)/factorial(r)
+
+
+defmain():
+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()