leetcode: 2022-06-24 LeetCode515_FindLargeValueInEachTreeRow

niumoo · niumoo · commit c881767bd754 · 2022-06-24T17:12:54.000+08:00
diff --git a/leetcode/src/main/java/com/wdbyte/leetcode/LeetCode515_FindLargeValueInEachTreeRow.java b/leetcode/src/main/java/com/wdbyte/leetcode/LeetCode515_FindLargeValueInEachTreeRow.java
@@ -0,0 +1,76 @@
+package com.wdbyte.leetcode;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * https://leetcode.cn/problems/find-largest-value-in-each-tree-row/
+ *
+ * 515. 在每个树行中找最大值
+ *
+ * @author niulang
+ * @date 2022/06/24
+ */
+public class LeetCode515_FindLargeValueInEachTreeRow {
+
+    public static void main(String[] args) {
+        LeetCode515_FindLargeValueInEachTreeRow code515 = new LeetCode515_FindLargeValueInEachTreeRow();
+        TreeNode tree3_5 = new TreeNode(5);
+        TreeNode tree3_3 = new TreeNode(3);
+        TreeNode tree3_9 = new TreeNode(9);
+        TreeNode tree2_3 = new TreeNode(3, tree3_5, tree3_3);
+        TreeNode tree2_2 = new TreeNode(2, null, tree3_9);
+        TreeNode tree1_1 = new TreeNode(1, tree2_3, tree2_2);
+        List<Integer> integers = code515.largestValues(tree1_1);
+        System.out.println(integers);
+    }
+
+    public List<Integer> largestValues(TreeNode root) {
+        List<Integer> result = new ArrayList<>();
+        if (root == null) {
+            return result;
+        }
+        List<TreeNode> nodeList = new ArrayList<>();
+        nodeList.add(root);
+        while (!nodeList.isEmpty()) {
+            List<TreeNode> nodeListTemp = new ArrayList<>();
+            Integer max = null;
+            for (TreeNode treeNode : nodeList) {
+                if (treeNode == null) {
+                    continue;
+                }
+                if (max == null) {
+                    max = treeNode.val;
+                }
+                if (max < treeNode.val) {
+                    max = treeNode.val;
+                }
+                if (treeNode.left != null) {
+                    nodeListTemp.add(treeNode.left);
+                }
+                if (treeNode.right != null) {
+                    nodeListTemp.add(treeNode.right);
+                }
+            }
+            result.add(max);
+            nodeList = nodeListTemp;
+        }
+        return result;
+    }
+}
+
+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;
+    }
+}
