cohalz

let bmi_check (name, height, weight) = 
  let bmi = weight /. (height *. height) in
  if bmi < 18.5 then name ^ "さんはやせています"
  else if bmi < 25.0 then name ^ "さんは標準です"
  else if bmi < 30.0 then name ^ "さんは肥満です"
  else name ^ "さんは肥満です"

cohalz

let geo_mean x y = sqrt(x *. y)

cohalz

let sum_and_diff (x, y) = (x + y, x - y)
let f (x, y) = ((x+y)/2,(x-y)/2)

cohalz

let rec pow(x,n) =
  if n <= 1 then x else x * pow(x,n-1)

cohalz

let rec pow(x,n) =
  if n <= 1 then x
  else let stack = pow(x,n/2) in
    if n mod 2 = 0 then stack*stack
    else x*stack*stack

cohalz

let rec iterpow(i,res,x,n) =
  if i > n then res else iterpow(i+1,res *. x,x,n)

cohalz

let rec gcd (m,n) =
  if m mod n = 0 then n else gcd(n,m mod n)

cohalz

let rec comb(n,m) =
  if m = 0 || n = m then 1
  else comb(n-1,m) + comb(n-1,m-1)

cohalz

let fib n =  
  let rec iterfib(i,pre2,pre1,res,n) =
    if i >= n then res else iterfib(i+1,pre1,res,res+pre1,n) in
    iterfib(1,0,0,1,n)

cohalz

let max_ascii str =
  let rec itermax(i,str,max,length) =
    if i >= length then max
    else if int_of_char(str.[i]) > max then itermax(i+1,str,int_of_char(str.[i]),length)
    else itermax(i+1,str,max,length) in
      itermax(0,str,0,String.length str)