Thinking process

Using binary search in the tree, until the root == null

Mistakes

• minDiff should be double
• when to use if and if, when to use if , else if
• when diff equals to MAX_VALUE?
• when diff is larger than MAX_VALUE? long?

public class Solution {

    public int closestValue(TreeNode root, double target) {

        int result = root.val;

        while (root != null) {
            if (root.val == target) {
                return root.val;
            }

            if (Math.abs(root.val - target) < Math.abs(result - target)) {
                result = root.val;
            }

            if (root.val > target) {
                root = root.left;
            } else if (root.val < target) {
                root = root.right;
            }
        }

        return result;
    }
}