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shimhun99 · shimhun99 · commit 10074c4ecb11 · 2026-04-09T04:52:04.000+09:00
diff --git a/LeetCode/Easy/0404-sum-of-left-leaves/0404-sum-of-left-leaves.java b/LeetCode/Easy/0404-sum-of-left-leaves/0404-sum-of-left-leaves.java
@@ -45,10 +45,10 @@ public int sumOfLeftLeaves(TreeNode root) {
     }
 
     void dfs(TreeNode node){
-        if(node == null) return;
+        // if(node == null) return;
         if(node.left!=null && node.left.left==null&&node.left.right==null) total+=node.left.val;
 
-        dfs(node.left);
-        dfs(node.right);
+        if(node.left!=null) dfs(node.left);
+        if(node.right!=null) dfs(node.right);
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -45,10 +45,10 @@ public int sumOfLeftLeaves(TreeNode root) {`
`45`	`45`	`}`
`46`	`46`
`47`	`47`	`void dfs(TreeNode node){`
`48`		`- if(node == null) return;`
	`48`	`+ // if(node == null) return;`
`49`	`49`	`if(node.left!=null && node.left.left==null&&node.left.right==null) total+=node.left.val;`
`50`	`50`
`51`		`- dfs(node.left);`
`52`		`- dfs(node.right);`
	`51`	`+ if(node.left!=null) dfs(node.left);`
	`52`	`+ if(node.right!=null) dfs(node.right);`
`53`	`53`	`}`
`54`	`54`	`}`