A tree rooted at node 0 is given as follows:
- The number of nodes is
nodes; - The value of the
i-th node isvalue[i]; - The parent of the
i-th node isparent[i].
Remove every subtree whose sum of values of nodes is zero.
After doing so, return the number of nodes remaining in the tree.
Example 1:
Input: nodes = 7, parent = [-1,0,0,1,2,2,2], value = [1,-2,4,0,-2,-1,-1] Output: 2
Example 2:
Input: nodes = 7, parent = [-1,0,0,1,2,2,2], value = [1,-2,4,0,-2,-1,-2] Output: 6
Example 3:
Input: nodes = 5, parent = [-1,0,1,0,0], value = [-672,441,18,728,378] Output: 5
Example 4:
Input: nodes = 5, parent = [-1,0,0,1,1], value = [-686,-842,616,-739,-746] Output: 5
Constraints:
1 <= nodes <= 10^4parent.length == nodes0 <= parent[i] <= nodes - 1parent[0] == -1which indicates that0is the root.value.length == nodes-10^5 <= value[i] <= 10^5- The given input is guaranteed to represent a valid tree.