112:路径总和
This commit is contained in:
parent
66c2b94686
commit
aeeae0b518
94
src/main/java/leetcode/editor/cn/PathSum.java
Normal file
94
src/main/java/leetcode/editor/cn/PathSum.java
Normal file
@ -0,0 +1,94 @@
|
||||
//给你二叉树的根节点 root 和一个表示目标和的整数 targetSum ,判断该树中是否存在 根节点到叶子节点 的路径,这条路径上所有节点值相加等于目标和
|
||||
// targetSum 。
|
||||
//
|
||||
// 叶子节点 是指没有子节点的节点。
|
||||
//
|
||||
//
|
||||
//
|
||||
// 示例 1:
|
||||
//
|
||||
//
|
||||
//输入:root = [5,4,8,11,null,13,4,7,2,null,null,null,1], targetSum = 22
|
||||
//输出:true
|
||||
//
|
||||
//
|
||||
// 示例 2:
|
||||
//
|
||||
//
|
||||
//输入:root = [1,2,3], targetSum = 5
|
||||
//输出:false
|
||||
//
|
||||
//
|
||||
// 示例 3:
|
||||
//
|
||||
//
|
||||
//输入:root = [1,2], targetSum = 0
|
||||
//输出:false
|
||||
//
|
||||
//
|
||||
//
|
||||
//
|
||||
// 提示:
|
||||
//
|
||||
//
|
||||
// 树中节点的数目在范围 [0, 5000] 内
|
||||
// -1000 <= Node.val <= 1000
|
||||
// -1000 <= targetSum <= 1000
|
||||
//
|
||||
// Related Topics 树 深度优先搜索 二叉树 👍 702 👎 0
|
||||
|
||||
package leetcode.editor.cn;
|
||||
|
||||
import com.code.leet.entiy.TreeNode;
|
||||
|
||||
//112:路径总和
|
||||
class PathSum {
|
||||
public static void main(String[] args) {
|
||||
//测试代码
|
||||
Solution solution = new PathSum().new Solution();
|
||||
}
|
||||
|
||||
//力扣代码
|
||||
//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 hasPathSum(TreeNode root, int targetSum) {
|
||||
if (root == null) {
|
||||
return false;
|
||||
}
|
||||
return dfs(root, 0, targetSum);
|
||||
}
|
||||
|
||||
private boolean dfs(TreeNode root, int sum, int targetSum) {
|
||||
if (root.left == null && root.right == null) {
|
||||
return root.val + sum == targetSum;
|
||||
}
|
||||
if (root.left != null) {
|
||||
if (dfs(root.left, sum + root.val, targetSum)) {
|
||||
return true;
|
||||
}
|
||||
}
|
||||
if (root.right != null) {
|
||||
return dfs(root.right, sum + root.val, targetSum);
|
||||
}
|
||||
return false;
|
||||
}
|
||||
}
|
||||
//leetcode submit region end(Prohibit modification and deletion)
|
||||
|
||||
}
|
37
src/main/java/leetcode/editor/cn/doc/content/PathSum.md
Normal file
37
src/main/java/leetcode/editor/cn/doc/content/PathSum.md
Normal file
@ -0,0 +1,37 @@
|
||||
<p>给你二叉树的根节点 <code>root</code> 和一个表示目标和的整数 <code>targetSum</code> ,判断该树中是否存在 <strong>根节点到叶子节点</strong> 的路径,这条路径上所有节点值相加等于目标和 <code>targetSum</code> 。</p>
|
||||
|
||||
<p><strong>叶子节点</strong> 是指没有子节点的节点。</p>
|
||||
|
||||
<p> </p>
|
||||
|
||||
<p><strong>示例 1:</strong></p>
|
||||
<img alt="" src="https://assets.leetcode.com/uploads/2021/01/18/pathsum1.jpg" style="width: 500px; height: 356px;" />
|
||||
<pre>
|
||||
<strong>输入:</strong>root = [5,4,8,11,null,13,4,7,2,null,null,null,1], targetSum = 22
|
||||
<strong>输出:</strong>true
|
||||
</pre>
|
||||
|
||||
<p><strong>示例 2:</strong></p>
|
||||
<img alt="" src="https://assets.leetcode.com/uploads/2021/01/18/pathsum2.jpg" />
|
||||
<pre>
|
||||
<strong>输入:</strong>root = [1,2,3], targetSum = 5
|
||||
<strong>输出:</strong>false
|
||||
</pre>
|
||||
|
||||
<p><strong>示例 3:</strong></p>
|
||||
|
||||
<pre>
|
||||
<strong>输入:</strong>root = [1,2], targetSum = 0
|
||||
<strong>输出:</strong>false
|
||||
</pre>
|
||||
|
||||
<p> </p>
|
||||
|
||||
<p><strong>提示:</strong></p>
|
||||
|
||||
<ul>
|
||||
<li>树中节点的数目在范围 <code>[0, 5000]</code> 内</li>
|
||||
<li><code>-1000 <= Node.val <= 1000</code></li>
|
||||
<li><code>-1000 <= targetSum <= 1000</code></li>
|
||||
</ul>
|
||||
<div><div>Related Topics</div><div><li>树</li><li>深度优先搜索</li><li>二叉树</li></div></div><br><div><li>👍 702</li><li>👎 0</li></div>
|
Loading…
Reference in New Issue
Block a user