Java for LeetCode 155 Min Stack

標籤：

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.

解題思路：

本題是 《JAVA語言程式設計-基礎篇》的原題，修改下即可，JAVA實現如下：

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;}}

 

Java for LeetCode 155 Min Stack