重拾算法之剑指Offier——包含min函数的栈

import java.util.Stack;

public class Solution {

Stack<Integer> stack1 = new Stack<Integer>();
Stack<Integer> stack2 = new Stack<Integer>();

public void push(int node) {

if (stack2.empty()){
stack2.push(node);
}else {
int top1 = stack1.peek();
if (top1 >= node){
stack2.push(node);
}else {
stack2.push(top1);
}
}
stack1.push(node);
}

public void pop() {
stack2.pop();
stack1.pop();

}

public int top() {
return stack1.peek();

}

public int min() {
return stack2.peek();
}
}