270:最接近的二叉搜索树值

src/main/java/leetcode/editor/cn/ClosestBinarySearchTreeValue.java

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+//给定一个不为空的二叉搜索树和一个目标值 target，请在该二叉搜索树中找到最接近目标值 target 的数值。 
+//
+// 注意： 
+//
+// 
+// 给定的目标值 target 是一个浮点数 
+// 题目保证在该二叉搜索树中只会存在一个最接近目标值的数 
+// 
+//
+// 示例： 
+//
+// 输入: root = [4,2,5,1,3]，目标值 target = 3.714286
+//
+//    4
+//   / \
+//  2   5
+// / \
+//1   3
+//
+//输出: 4
+// 
+// Related Topics 树 深度优先搜索 二叉搜索树 二分查找 二叉树 👍 112 👎 0
+
+package leetcode.editor.cn;
+
+import com.code.leet.entiy.TreeNode;
+
+//270:最接近的二叉搜索树值
+public class ClosestBinarySearchTreeValue {
+    public static void main(String[] args) {
+        Solution solution = new ClosestBinarySearchTreeValue().new Solution();
+        // TO TEST
+    }
+    //leetcode submit region begin(Prohibit modification and deletion)
+
+    /**
+     * Definition for a binary tree node.
+     * public class TreeNode {
+     * int val;
+     * TreeNode left;
+     * TreeNode right;
+     * TreeNode() {}
+     * TreeNode(int val) { this.val = val; }
+     * TreeNode(int val, TreeNode left, TreeNode right) {
+     * this.val = val;
+     * this.left = left;
+     * this.right = right;
+     * }
+     * }
+     */
+    class Solution {
+        public int closestValue(TreeNode root, double target) {
+            double left = target;
+            double right = target;
+            float diff = 1e-6f;
+            while (root != null) {
+                if (Math.abs(root.val - target) < diff) {
+                    return root.val;
+                }
+                if (root.val > target) {
+                    right = root.val;
+                    root = root.left;
+                } else {
+                    left = root.val;
+                    root = root.right;
+                }
+            }
+
+            if (Math.abs(left - target) < diff) {
+                return (int) right;
+            } else if (Math.abs(right - target) < diff) {
+                return (int) left;
+            } else {
+                return target - left > right - target ? (int) right : (int) left;
+            }
+        }
+    }
+//leetcode submit region end(Prohibit modification and deletion)
+
+}

src/main/java/leetcode/editor/cn/doc/content/ClosestBinarySearchTreeValue.md

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+<p>给定一个不为空的二叉搜索树和一个目标值 target，请在该二叉搜索树中找到最接近目标值 target 的数值。</p>
+
+<p><strong>注意：</strong></p>
+
+<ul>
+	<li>给定的目标值 target 是一个浮点数</li>
+	<li>题目保证在该二叉搜索树中只会存在一个最接近目标值的数</li>
+</ul>
+
+<p><strong>示例：</strong></p>
+
+<pre><strong>输入:</strong> root = [4,2,5,1,3]，目标值 target = 3.714286
+
+    4
+   / \
+  2   5
+ / \
+1   3
+
+<strong>输出:</strong> 4
+</pre>
+<div><div>Related Topics</div><div><li>树</li><li>深度优先搜索</li><li>二叉搜索树</li><li>二分查找</li><li>二叉树</li></div></div><br><div><li>👍 112</li><li>👎 0</li></div>