每次找到数组中的最大值，然后递归的构建左右树

public TreeNode constructMaximumBinaryTree(int[] nums) {        if (nums.length==0) return null;        return builder(nums,0,nums.length-1);    }    public TreeNode builder(int[] nums,int sta,int end)    {        /*        思路就是每次找到最大值，然后分为两个子数组递归构建左右树         */        if (sta>end) return null;        int max = Integer.MIN_VALUE;        int index = -1;        for (int i = sta; i <= end ; i++) {            if (nums[i]>max)            {                max = nums[i];                index = i;            }        }        TreeNode root = new TreeNode(max);        root.left = builder(nums,sta,index-1);        root.right = builder(nums,index+1,end);        return root;    }