Double recursion function

Ackermann Function is defined as

ack(0,n) = n + 1
ack(m,0) = ack( m-1, 1)
ack(m,n) = ack( m – 1, ack( m, n – 1 ))


For example
ack( 1, 1 )
= ack ( 0, ack ( 1, 0 ) )
= ack ( 0 , ack( 0, 1 ) )
= ack ( 0, 2 )
= 3

Try to work out ack( 1 , 2 ) and ack ( 1, 3 ) by hand.

Write a program that will accept two parameters and display the value of the corresponding Ackermann function. For example:


$ ack 1 1

The Ackermann value of ack(1,1) is 3

Using your program, try to find out the values of ack(2,3), ack(3,2) and ack(4,2).
WARNING!!!! It may not be as easy as it looks

版主啊！你那结果怎么做出来的啊，帮帮忙吧