Sum of all elements of N-ary Tree

The approach used is similar to Level Order traversal in a binary tree. Start by pushing the root node in the queue. And for each node, while popping it from queue, add the value of this node in the sum variable and push the children of the popped element in the queue. In case of a generic tree store child nodes in a vector. Thus, put all elements of the vector in the queue.

Sum of all elements of N-ary Tree: https://www.geeksforgeeks.org/sum-elements-n-ary-tree/