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;
}
}