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| class Solution {
private static class ResultHolder {
private int sumOfLeftLeaves;
}
public int sumOfLeftLeaves(TreeNode root) {
ResultHolder resultHolder = new ResultHolder();
dfs(resultHolder, root, false);
return resultHolder.sumOfLeftLeaves;
}
private void dfs(ResultHolder resultHolder, TreeNode root, boolean isLeft) {
if (root.left == null && root.right == null) {
if (isLeft) {
resultHolder.sumOfLeftLeaves += root.val;
}
}
if (root.left != null) {
dfs(resultHolder, root.left, true);
}
if (root.right != null) {
dfs(resultHolder, root.right, false);
}
}
}
|