algorithm/Week_02/id_30/LeetCode_783_30.java at master · algorithm001/algorithm · GitHub

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package com.shufeng.algorithm.d0_;

/**

* @author gsf

public class LeetCode_783_30 {

public static void main(String[] args) {

TreeNode bst = new TreeNode(4);

bst.left = new TreeNode(2);

bst.right = new TreeNode(6);

bst.left.left = new TreeNode(1);

bst.left.right = new TreeNode(3);

int i = minDiffInBST(bst);

System.out.println(i);

}

public static int minDiffInBST(TreeNode root) {

if (root == null) {

return -1;

}

List<Integer> list = new ArrayList<>();

minDiffInBST(root, list);

int num = Integer.MAX_VALUE;

for (int i = 1; i < list.size(); i++) {

num = Math.min(num, list.get(i) - list.get(i - 1));

}

return num;

}

public static void minDiffInBST(TreeNode root, List<Integer> list) {

if (root == null) {

return;

}

minDiffInBST(root.left, list);

list.add(root.val);

minDiffInBST(root.right, list);

}

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