problem_tossing_coins.R

return_tosses <- function(value1, value2) {
  t1 <- rbinom(1,1,.5)
  i <- 1
  while ( TRUE ) {
    t2 <- rbinom(1,1,.5)
    i <- i + 1
    if ( t1 == value1 & t2 == value2)
      return(i)
    t1 <- t2
  }
}

N <- 100000
alice <- vector(mode="integer",length=N)
bob <- vector(mode="integer",length=N)

# 1 = head, 0 = tail
for (i in 1:N) {
  alice[i] <- return_tosses(1,0)  
  bob[i] <- return_tosses(1,1)  

}

mean(alice)
## [1] 3.99914
mean(bob)
## [1] 5.97424