CTCI 3.6

/*Use bubble sort, one stack used as buffer as well as to store the sorted elements. 
Each time find the smallest element exist in the other stack and push it in after pop the buffer out.*/
import java.util.*;

public class SortStack {
    Stack<Integer> stack2 = new Stack<Integer>();

    public void sort(Stack<Integer> stack1) {
        int min = 0, temp = 0, cnt = 0;
        while(stack1.isEmpty() == false) {
            stack2.push(stack1.pop());
            cnt++;
        }

        for(int i = 0; i < cnt; i++) {
            min = stack2.pop();
            while(stack2.isEmpty() == false) {
                temp = stack2.pop();
                if(temp >= min) {
                    stack1.push(temp);
                }
                else {
                    stack1.push(min);
                    min = temp;
                }
            }
            for(int j = 0; j < cnt-i-1; j++) {
                stack2.push(stack1.pop());
            }
            stack1.push(min);
        }
    }

    public void print(Stack<Integer> stack) {
        while(stack.isEmpty() == false) {
            System.out.print(stack.pop() + " ");
        }
        System.out.print("");
    }

    public static void main(String[] args) {
        Stack<Integer> stack1 = new Stack<Integer>();
        stack1.push(10); stack1.push(8); stack1.push(18); stack1.push(8); stack1.push(1);
        SortStack ss = new SortStack();
        ss.sort(stack1);
        ss.print(stack1);
    }
}