private static void PreOrder(LeetCode1022TreeNode root, int currSum)
{
if (root == null)
{
return;
}
//visit the root;
currSum = (currSum << 1) | root.val;
// base case
if (root.left == null && root.right == null)
{
ans += currSum;
}
// visit the left
PreOrder(root.left, currSum);
//visit the right;
PreOrder(root.right, currSum);
}
public LeetCode1022TreeNode(int val = 0, LeetCode1022TreeNode left = null, LeetCode1022TreeNode right = null)
{
this.val = val;
this.left = left;
this.right = right;
}
public static int SumRootToLeafRecursive(LeetCode1022TreeNode root)
{
PreOrder(root, 0);
return(ans);
}
