965:单值二叉树

2022-05-24 10:20:51 +08:00 · 2022-05-24 10:20:51 +08:00 · 7ab68e8f84
commit 7ab68e8f84
parent aead51e257
2 changed files with 112 additions and 0 deletions
--- a/src/main/java/leetcode/editor/cn/UnivaluedBinaryTree.java
+++ b/src/main/java/leetcode/editor/cn/UnivaluedBinaryTree.java
@ -0,0 +1,81 @@
+//<p>如果二叉树每个节点都具有相同的值，那么该二叉树就是<em>单值</em>二叉树。</p>
+//
+//<p>只有给定的树是单值二叉树时，才返回&nbsp;<code>true</code>；否则返回 <code>false</code>。</p>
+//
+//<p>&nbsp;</p>
+//
+//<p><strong>示例 1：</strong></p>
+//
+//<p><img alt="" src="https://assets.leetcode-cn.com/aliyun-lc-upload/uploads/2018/12/29/screen-shot-2018-12-25-at-50104-pm.png" style="height: 159px; width: 200px;"></p>
+//
+//<pre><strong>输入：</strong>[1,1,1,1,1,null,1]
+//<strong>输出：</strong>true
+//</pre>
+//
+//<p><strong>示例 2：</strong></p>
+//
+//<p><img alt="" src="https://assets.leetcode-cn.com/aliyun-lc-upload/uploads/2018/12/29/screen-shot-2018-12-25-at-50050-pm.png" style="height: 158px; width: 200px;"></p>
+//
+//<pre><strong>输入：</strong>[2,2,2,5,2]
+//<strong>输出：</strong>false
+//</pre>
+//
+//<p>&nbsp;</p>
+//
+//<p><strong>提示：</strong></p>
+//
+//<ol>
+//	<li>给定树的节点数范围是&nbsp;<code>[1, 100]</code>。</li>
+//	<li>每个节点的值都是整数，范围为&nbsp;<code>[0, 99]</code>&nbsp;。</li>
+//</ol>
+//<div><div>Related Topics</div><div><li>树</li><li>深度优先搜索</li><li>广度优先搜索</li><li>二叉树</li></div></div><br><div><li>👍 121</li><li>👎 0</li></div>
+package leetcode.editor.cn;
+
+import com.code.leet.entiy.TreeNode;
+
+// 965:单值二叉树
+public class UnivaluedBinaryTree {
+    public static void main(String[] args) {
+        Solution solution = new UnivaluedBinaryTree().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 boolean isUnivalTree(TreeNode root) {
+            return isSame(root, root.val);
+        }
+
+        private boolean isSame(TreeNode node, int val) {
+            if (node == null) {
+                return true;
+            }
+            if (node.val != val) {
+                return false;
+            }
+            boolean is = true;
+            is = is && isSame(node.left, val);
+            if (!is) {
+                return false;
+            }
+            return is && isSame(node.right, val);
+        }
+    }
+//leetcode submit region end(Prohibit modification and deletion)
+
+}
--- a/src/main/java/leetcode/editor/cn/doc/content/UnivaluedBinaryTree.md
+++ b/src/main/java/leetcode/editor/cn/doc/content/UnivaluedBinaryTree.md
@ -0,0 +1,31 @@
+<p>如果二叉树每个节点都具有相同的值，那么该二叉树就是<em>单值</em>二叉树。</p>
+
+<p>只有给定的树是单值二叉树时，才返回&nbsp;<code>true</code>；否则返回 <code>false</code>。</p>
+
+<p>&nbsp;</p>
+
+<p><strong>示例 1：</strong></p>
+
+<p><img alt="" src="https://assets.leetcode-cn.com/aliyun-lc-upload/uploads/2018/12/29/screen-shot-2018-12-25-at-50104-pm.png" style="height: 159px; width: 200px;"></p>
+
+<pre><strong>输入：</strong>[1,1,1,1,1,null,1]
+<strong>输出：</strong>true
+</pre>
+
+<p><strong>示例 2：</strong></p>
+
+<p><img alt="" src="https://assets.leetcode-cn.com/aliyun-lc-upload/uploads/2018/12/29/screen-shot-2018-12-25-at-50050-pm.png" style="height: 158px; width: 200px;"></p>
+
+<pre><strong>输入：</strong>[2,2,2,5,2]
+<strong>输出：</strong>false
+</pre>
+
+<p>&nbsp;</p>
+
+<p><strong>提示：</strong></p>
+
+<ol>
+	<li>给定树的节点数范围是&nbsp;<code>[1, 100]</code>。</li>
+	<li>每个节点的值都是整数，范围为&nbsp;<code>[0, 99]</code>&nbsp;。</li>
+</ol>
+<div><div>Related Topics</div><div><li>树</li><li>深度优先搜索</li><li>广度优先搜索</li><li>二叉树</li></div></div><br><div><li>👍 121</li><li>👎 0</li></div>