2019-10-17 10:11:24 +02:00
|
|
|
// This program displays the fibonacci sequence
|
|
|
|
|
|
|
|
import os
|
|
|
|
|
|
|
|
fn main() {
|
|
|
|
// Check for user input
|
|
|
|
if os.args.len != 2 {
|
|
|
|
println('usage: fibonacci [rank]')
|
|
|
|
|
|
|
|
// Exit
|
|
|
|
return
|
|
|
|
}
|
|
|
|
|
|
|
|
// Parse first argument and cast it to int
|
|
|
|
stop := os.args[1].int()
|
|
|
|
|
2019-10-30 12:54:38 +01:00
|
|
|
// Can only calculate correctly until rank 92
|
|
|
|
if stop > 92 {
|
|
|
|
println('rank must be 92 or less')
|
|
|
|
return
|
|
|
|
}
|
|
|
|
|
2019-10-17 10:11:24 +02:00
|
|
|
// Three consecutive terms of the sequence
|
2019-10-30 12:54:38 +01:00
|
|
|
mut a := u64(0)
|
|
|
|
mut b := u64(0)
|
|
|
|
mut c := u64(1)
|
2019-10-17 10:11:24 +02:00
|
|
|
|
2020-05-13 14:51:11 +02:00
|
|
|
for _ in 0..stop {
|
2019-10-17 10:11:24 +02:00
|
|
|
// Set a and b to the next term
|
|
|
|
a = b
|
|
|
|
b = c
|
|
|
|
// Compute the new term
|
|
|
|
c = a + b
|
|
|
|
|
|
|
|
// Print the new term
|
|
|
|
println(c)
|
|
|
|
}
|
|
|
|
}
|