---

Lỗi biên dịch:

Main.cc:8:5: error: expected initializer before ‘double’
     double approximatePi(int n) {
     ^~~~~~
Main.cc: In function ‘int main()’:
Main.cc:24:21: error: ‘approximatePi’ was not declared in this scope
     double result = approximatePi(n);
                     ^~~~~~~~~~~~~