Sort Using Two Stacks
Write a program to sort a stack using additional stacks but no other data structures
import scala.collection.mutable.Stack
/**
* 3.6
* @param s1
* @return
*/
def sort(s1:Stack[Int]): Stack[Int] = {
val s2 = Stack[Int]()
while (!s1.isEmpty) {
val tmp = s1.pop()
while (!s2.isEmpty && s2.head < tmp) {
s1.push(s2.pop())
}
s2.push(tmp)
}
s2
}
val s = Stack[Int]()
s.push(3)
s.push(9)
s.push(5)
val s3 = sort(s)
while (!s3.isEmpty) {
println(s3.pop())
}
