January 10, 2025 |9.2K Views

    Root to leaf path sum equal to a given number

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    Given a binary tree and a number, return true if the tree has a root-to-leaf path such that adding up all the values along the path equals the given number. Return false if no such path can be found. 

    Example:

    Input:      10          Sum = 23
                 /     \
              8        2
           /    \     /
         3      5  2

    Output: True 
    Explanation:  Root to leaf path sum, existing in this tree are
    21 –> 10 – 8 – 3 
    23 –> 10 – 8 – 5 
    14 –> 10 – 2 – 2
    So it is possible to get sum = 23

    Follow the given steps to solve the problem using the above approach:

    • Recursively move to the left and right subtree and at each call decrease the sum by the value of the current node

    • If at any level the current node is a leaf node and the remaining sum is equal to zero then return true

    Related Articles : https://www.geeksforgeeks.org/root-to-leaf-path-sum-equal-to-a-given-number/