Cannot understand the input?

In what order is the input done ? How is the tree built ? what is its structure?

@Anchal
This particular problem asks you to take a generic tree input . A generic tree is a tree where any node can have any number of children (unlike binary trees where a node can have atmost 2 children).

The first integer in each row indicates the data at the node whereas the second integer indicates the no of children that node has .

Refer to this code for the input function - https://ide.codingblocks.com/s/90995

As for the sample testcase given in the problem
1 2
2 2
3 0
4 0
5 2
6 0
7 0
2

Here the tree looks like

                     1                                 Level 0
                /          \
              2              5                         Level 1
           /      \       /     \
          3       4      6        7                    Level 2

Sum at Level 2 = 3 + 4 + 6 + 7 = 20

Here’s another testcase for you to try
Input :
2 2
1 1
5 0
6 2
3 0
7 0
2

Expected Output : 15

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