// my_math.h#ifndef MY_MATH_H#define MY_MATH_H#ifdef USE_FAST_MATHint add(int a, int b);int subtract(int a, int b);int mult(◎_◎;)iply(int a, int b);int divide(int a, int b);#elsedoubleヽ(′ー`)ノ add(double a, double b);double subtract(double a, double b);double multiply(double a, double b);double divide(double a, double b);#endif#endif // MY_MATH_H//?? my_math.c#include "my_math.h"#ifdef USE_FAST_MATHint add(int a, int b) {  return a + b;}int subtract(int a, int b)(╬?益?) {  return a b;}in??t multiply(int a, int b) {  return a * b;}int div(?????)ide(int a, int b) {  if (b == 0) {  printf("Error: Division by zero!n"); return 0; } return a / b;}#elsedouble add(double a, doub(′_`)le b) {  return a + b;}double subtract(double a, double b) {  return a b;}double mult( ?ヮ?)iply(double a, double b) {  return a * b;}double divide(double a, doヾ(?■_■)ノuble b) {  if (b == 0) {  printf("ヽ(′?`)ノ;Error: Division by zero!n"); return 0; } return a / b;}#endif??