Assignment Homework-2: Create a user chooser function

Step-1: Create a function factn for n Factorial

Function factn(n)

range: for n >= 0

factn <- function(n)
  {factorial <- 1;
  if(n == 0) {
    factorial <- 1}
  else 
    for(i in 1:n) {
        factorial <- factorial*i
    }
   return(factorial)
 }

Testing of Factorial Function factn

# Test-1a
# factn expected answer is 6
factn(3)
## [1] 6
# Test-1b
# factn expected answer is 720
factn(6)
## [1] 720

Step-2: Write a user choose Function named choose1(n,r)

Range: for n >= 0, and r >=0

choose1 <- function(n,r)
{cout <- factn(n) / (factn(n-r) * factn(r))
  return(cout)
}

Testing of user function choose1

#Test-2a
# expected answer is 10
choose1(5,3)
## [1] 10
# R function answer to validate
choose(5,3)
## [1] 10
#Test-2b
# Custom choose1 expected answer is 70
choose1(8,4)
## [1] 70
#R function answer to validate
choose(8,4)
## [1] 70

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