private static int Count(LeetCode437Node root, int sum)
{
if (root == null)
{
return(0);
}
var baseVal = root.val == sum ? 1 : 0;
var left = Count(root.left, sum - root.val);
var right = Count(root.right, sum - root.val);
return(baseVal + left + right);
}
public static int PathSum(LeetCode437Node root, int sum)
{
if (root == null)
{
return(0);
}
var pathLeadingCount = Count(root, sum);
var leftPathSum = PathSum(root.left, sum);
var rightPathSum = PathSum(root.right, sum);
return(pathLeadingCount + leftPathSum + rightPathSum);
}
public LeetCode437Node(int val = 0, LeetCode437Node left = null, LeetCode437Node right = null)
{
this.val = val;
this.left = left;
this.right = right;
}
