算法

链表反转

public static LinkListTest reverse(LinkListTest link) {
if (link == null || link.getNext() == null) {
return link; }
LinkListTest curNode = link.getNext(); link.setNext(null); while (curNode != null) {
LinkListTest nextNode = curNode.getNext(); curNode.setNext(link); link = curNode; curNode = nextNode; }
return link;}

栈实现队列

public class QueueDemo {

//先进后出  实现先进先出    private Stack<Integer> stack = null;    private Stack<Integer> temp = null;<br />    public QueueDemo() {<br />        stack = new Stack<>();        temp = new Stack<>();    }
/*<br />     */    public void push(Integer value) {<br />        stack.push(value);// 1 2 3 4    }
public Integer pop() {<br />        Integer result = null;//        temp.clear();        // 拿出来 放进去  如何优化   空判断        if (!temp.isEmpty()){<br />            result =temp.pop();        }else {<br />            while (!stack.isEmpty()){<br />                temp.push(stack.pop());            }<br />            if (!temp.isEmpty()){<br />                result = temp.pop();            }<br />        }<br />        return result;    }
public static void main(String[] args) {<br />        QueueDemo queueDemo = new QueueDemo();        queueDemo.push(1);        queueDemo.push(2);        queueDemo.push(3);        queueDemo.push(4);<br />        System._out_.println(queueDemo.pop());        System._out_.println(queueDemo.pop());        System._out_.println(queueDemo.pop());        System._out_.println(queueDemo.pop());        System._out_.println(queueDemo.pop());<br />    }

}

冒泡排序

/当前循环如果没有变化，说明
/public int[] maopaoSort(int[] nums) {
boolean hasChange = true; for (int i = 0; i < nums.length && hasChange; i++) {
hasChange = false; for (int j = 0; j < nums.length - 1 - i; j++) {
if (nums[j] > nums[j + 1]) {
hasChange = true; int temp = nums[j]; nums[j] = nums[j + 1]; nums[j + 1] = temp; }
}
}
System.out.println(Arrays.toString(nums)); return nums;}

插入排序

public int[] charuSort(int[] nums) {
for (int i = 1, j, current; i < nums.length; i++) {
current = nums[i]; for (j = i - 1; j >= 0 && nums[j] > current; j—) {
nums[j + 1] = nums[j]; }
System.out.println(j); nums[j + 1] = current; }
System.out.println(Arrays.toString(nums)); return nums;}

计算二叉树深度

回文判断