Java for LeetCode 155 Min Stack

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.

    push(x) -- Push element x onto stack.
    pop() -- Removes the element on top of the stack.
    top() -- Get the top element.
    getMin() -- Retrieve the minimum element in the stack.

解题思路：

本题是 《JAVA语言程序设计-基础篇》的原题，修改下即可，JAVA实现如下：

public class MinStack {
	private int[] elements;
	private int size;
	
	public MinStack() {
		elements = new int[16];
	}

	public void push(int x) {
		if (size >= elements.length) {
			int[] temp = new int[elements.length * 2];
			System.arraycopy(elements, 0, temp, 0, elements.length);
			elements = temp;
		}
		elements[size++] = x;
	}

	public void pop() {
		size--;
	}

	public int top() {
		return elements[size - 1];
	}

	public int getMin() {
		int min=Integer.MAX_VALUE;
		for(int i=0;i<size;i++)
			if(min>elements[i])
				min=elements[i];
		return min;
	}
}