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Posted: 27 Mar, 2021

Difficulty: Easy

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Consider the following binary tree :
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So the sum of child nodes having even valued grandparents is ‘4 + 8 + 1 + 9 + 2 = 24’
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The first line contains an integer ‘T' which denotes the number of test cases to be run. Then the test cases follow.
The first line of each test case contains the tree elements in the level order form separated by a single space.
If any node does not have a left or right child, take -1 in its place. Refer to the example below.
Example :
Elements are in the level order form. The input consists of values of nodes separated by a single space in a single line. In case a node is null, we take -1 in its place.
For example, the input for the tree depicted in the below image would be :
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```
1
2 3
4 -1 5 6
-1 7 -1 -1 -1 -1
-1 -1
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Level 1 :
The root node of the tree is 1
Level 2 :
Left child of 1 = 2
Right child of 1 = 3
Level 3 :
Left child of 2 = 4
Right child of 2 = null (-1)
Left child of 3 = 5
Right child of 3 = 6
Level 4 :
Left child of 4 = null (-1)
Right child of 4 = 7
Left child of 5 = null (-1)
Right child of 5 = null (-1)
Left child of 6 = null (-1)
Right child of 6 = null (-1)
Level 5 :
Left child of 7 = null (-1)
Right child of 7 = null (-1)
The first not-null node (of the previous level) is treated as the parent of the first two nodes of the current level. The second not-null node (of the previous level) is treated as the parent node for the next two nodes of the current level and so on.
The input ends when all nodes at the last level are null (-1).
```

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The above format was just to provide clarity on how the input is formed for a given tree.
The sequence will be put together in a single line separated by a single space. Hence, for the above-depicted tree, the input will be given as:
1 2 3 4 -1 5 6 -1 7 -1 -1 -1 -1 -1 -1
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For each test case, print the sum of all child nodes having even valued grandparent nodes.
Print output of each test case in a separate line.
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You are not required to print anything. It has already been taken care of. Just implement the function.
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```
1 <= T <= 100
1 <= N <= 3000
0 <= data <= 10^9
Where ‘T’ is the total number of test cases, ‘N’ is the number of nodes of the tree, and ‘data’ is the integer value mentioned on the node.
Time Limit : 1 sec
```

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