please i need asap help with these ( Data structure and algorithm)

10. Write a C++ recursive function that performs the calculation described in the following equation: (10 pts) f(n)={f(n1)+n10ifn>1ifn=1 11. The following left figure presents a binary tree example, and the right figure shows the mirror image of the left binary tree. Then, design an algorithm to change a given input binary tree so that it becomes the mirror image of the original binary tree. (10pts)