LeetCode #112 Path Sum Solution & Explanation

public class Solution {
    public bool HasPathSum(TreeNode root, int targetSum) {
        if (root == null) {
            return false;
        }

        //minus value of current node
        targetSum -= root.val;
        
        //check if now a leaf node
        if (root.left == null && root.right == null) {
            return targetSum == 0;
        }

        return HasPathSum(root.left, targetSum) || HasPathSum(root.right, targetSum);
    }
}

class Solution {
    public boolean hasPathSum(TreeNode root, int targetSum) {
        if (root == null) {
            return false;
        }

        //minus value of current node
        targetSum -= root.val;
        
        //check if now a leaf node
        if (root.left == null && root.right == null) {
            return targetSum == 0;
        }

        return hasPathSum(root.left, targetSum) || hasPathSum(root.right, targetSum);
    }
}

class Solution:
    def hasPathSum(self, root: Optional[TreeNode], targetSum: int) -> bool:
        if(root==None):
            return False
        
        #minus value of current node
        targetSum = targetSum-root.val
        
        #check if now a leaf node
        if (root.left == None and root.right == None):
            return targetSum == 0
        
        return self.hasPathSum(root.left, targetSum) or self.hasPathSum(root.right, targetSum)

var hasPathSum = function(root, targetSum) {
    if (root == null) {
        return false;
    }

    //minus value of current node
    targetSum -= root.val;
    
    //check if now a leaf node
    if (root.left == null && root.right == null) {
        return targetSum == 0;
    }

    return hasPathSum(root.left, targetSum) || hasPathSum(root.right, targetSum);
};