一刷1110

Author: diguage

README.adoc

@@ -7796,13 +7796,13 @@ TIP: **公众号的微信号是: `jikerizhi`**。__因为众所周知的原因
 |Medium
 |
 
-//|{counter:codes}
-//|{leetcode_base_url}/delete-nodes-and-return-forest/[1110. Delete Nodes And Return Forest^]
-//|{source_base_url}/_1110_DeleteNodesAndReturnForest.java[Java]
-//|{doc_base_url}/1110-delete-nodes-and-return-forest.adoc[题解]
-//|Medium
-//|
-//
+|{counter:codes}
+|{leetcode_base_url}/delete-nodes-and-return-forest/[1110. Delete Nodes And Return Forest^]
+|{source_base_url}/_1110_DeleteNodesAndReturnForest.java[Java]
+|{doc_base_url}/1110-delete-nodes-and-return-forest.adoc[题解]
+|Medium
+|
+
 //|{counter:codes}
 //|{leetcode_base_url}/maximum-nesting-depth-of-two-valid-parentheses-strings/[1111. Maximum Nesting Depth of Two Valid Parentheses Strings^]
 //|{source_base_url}/_1111_MaximumNestingDepthOfTwoValidParenthesesStrings.java[Java]

docs/1110-delete-nodes-and-return-forest.adoc

@@ -29,11 +29,18 @@ image::https://assets.leetcode.com/uploads/2019/07/01/screen-shot-2019-07-01-at-
 * `to_delete.length <= 1000`
 * `to_delete` contains distinct values between `1` and `1000`.
 
+== 思路分析
 
+利用递归，在“后序遍历”阶段，对当前阶段判断是否需要删除。
 
 [[src-1110]]
 [{java_src_attr}]
 ----
 include::{sourcedir}/_1110_DeleteNodesAndReturnForest.java[tag=answer]
 ----
 
+== 参考资料
+
+. https://leetcode.cn/problems/delete-nodes-and-return-forest/solutions/2286145/shan-dian-cheng-lin-by-leetcode-solution-gy95/[1110. 删点成林 - 官方题解^]
+. https://leetcode.cn/problems/delete-nodes-and-return-forest/solutions/2289131/he-shi-ji-lu-da-an-pythonjavacgo-by-endl-lpcd/[1110. 删点成林 - 简洁写法！^]
+

docs/index.adoc

@@ -2294,7 +2294,7 @@ include::1094-car-pooling.adoc[leveloffset=+1]
 
 include::1109-corporate-flight-bookings.adoc[leveloffset=+1]
 
-// include::1110-delete-nodes-and-return-forest.adoc[leveloffset=+1]
+include::1110-delete-nodes-and-return-forest.adoc[leveloffset=+1]
 
 // include::1111-maximum-nesting-depth-of-two-valid-parentheses-strings.adoc[leveloffset=+1]
 

logbook/202406.adoc

@@ -888,6 +888,10 @@
 |{doc_base_url}/0892-surface-area-of-3d-shapes.adoc[题解]
 |✅ 计算几个柱子的面积
 
+|{counter:codes}
+|{leetcode_base_url}/delete-nodes-and-return-forest/[1110. Delete Nodes And Return Forest^]
+|{doc_base_url}/1110-delete-nodes-and-return-forest.adoc[题解]
+|✅ 递归+深度优先
 
 |===
 

src/main/java/com/diguage/algo/leetcode/_1110_DeleteNodesAndReturnForest.java

@@ -0,0 +1,53 @@
+package com.diguage.algo.leetcode;
+
+import com.diguage.algo.util.TreeNode;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class _1110_DeleteNodesAndReturnForest {
+  // tag::answer[]
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2024-09-27 15:06:39
+   */
+  public List<TreeNode> delNodes(TreeNode root, int[] to_delete) {
+    List<TreeNode> result = new ArrayList<>();
+    Set<Integer> deletes = Arrays.stream(to_delete)
+      .boxed().collect(Collectors.toUnmodifiableSet());
+    TreeNode tree = dfs(root, deletes, result);
+    if (tree != null) {
+      result.add(tree);
+    }
+    return result;
+  }
+
+  private TreeNode dfs(TreeNode root, Set<Integer> deletes, List<TreeNode> result) {
+    if (root == null) {
+      return null;
+    }
+    TreeNode left = dfs(root.left, deletes, result);
+    TreeNode right = dfs(root.right, deletes, result);
+    if (deletes.contains(root.val)) {
+      if (left != null) {
+        result.add(left);
+      }
+      if (right != null) {
+        result.add(right);
+      }
+      return null;
+    } else {
+      if (left == null) {
+        root.left = null;
+      }
+      if (right == null) {
+        root.right = null;
+      }
+      return root;
+    }
+  }
+  // end::answer[]
+}