LeetCode530-二叉搜索树的最小绝对差

LeetCode530-二叉搜索树的最小绝对差

中序递归实现

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int pre = -1;
    int min = Integer.MAX_VALUE;

    public int getMinimumDifference(TreeNode root) {
        inorderTraversal(root);
        return min;
    }

    private void inorderTraversal(TreeNode node) {
        if (node == null) {
            return;
        }
        inorderTraversal(node.left);
        if (pre==-1){
            pre = node.val;
        }else {
            min = Math.min(min, node.val - pre);
            pre = node.val;
        }
        inorderTraversal(node.right);
    }