求写C语言计算器代码,要求加减乘除,求余数,阶乘,累加,排列,组合

#include
#include
#include
double EPS=10E-6;
double sum(double a,double b)
{
return a+b;
}
double sub(double a,double b)
{
return a-b;
}
double mul(double a,double b)
{
return a*b;
}
double divv(double a,double b)
{
return a/b;
}
int rem(int a , int b)
{
return a%b;
}
int addnumber(int c,int d)
{
int sum=0;
for(int i=c;i