$//$ Returns the maximum, minimum, and average area of shapes in the tree

$//$ An empty tree should not modify the maximum, minimum, or average

void max$\_$min$\_$avg$\_$area$($tree$\_$node$\_$t$*$ root, double$*$ max, double$*$ min, double$*$ avg$)$

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$ Executes the func function for each node in the tree in$-$order

$//$ The function takes in an input data and returns an output data, which is used as input to the next call to the function

$//$ The initial input data is provided as a parameter to foreach, and foreach returns the final output data

$//$ For example, if there are three nodes, foreach should behave like: return func$($node$3,$ func$($node$2,$ func$($node$1,$ data$)))$

double foreach$($tree$\_$node$\_$t$*$ root, foreach$\_$fn func, double data$)$

$\{$

$//$ IMPLEMENT THIS

return data;

$\}$