二叉搜索树的最小绝对差 ​

var getMinimumDifference = function(root) {
    const arr = []
    digui(root,arr)
    console.log(arr)
    let ans = arr[arr.length-1]
    for (let i = 1; i < arr.length; i++) {	//遍历数组统计最小差值
        ans = Math.min(arr[i]-arr[i-1],ans)
    }
    return ans

};

//中序遍历转换成有序数组
var digui = function(root,arr) {
   if(root===null)  return
   digui(root.left,arr)
   arr.push(root.val)
   digui(root.right,arr)
};

var getMinimumDifference = function(root) {
    let min = 5+10e4
    let pre = null
    const digui = (cur) =>{     //中序遍历
        if(cur===null)  return
        digui(cur.left)
        if(pre!=null)
                min = Math.min(Math.abs(pre.val-cur.val),min)
            pre = cur
        digui(cur.right)
    }
    digui(root)
    return min
};