编程题目，此函数的第一个参数接收函数指针。

#include

double result;

double sum(double x, double y)
{
result = x + y;
return result;
}
double sub(double x, double y)
{
result = x - y;
return result;
}
double mult(double x, double y)
{
result = x * y;
return result;
}
double divs(double x, double y)
{
result = x / y;
return result;
}

double Computer(double (*p)(double x,double y), double x,double y)
{
result = p(x,y);
return result;
}
int main(void)
{
double r1,r2,r3,r4;
r1 = Computer( & sum, 6, 7);
r2 = Computer( & sub, 6, 7);
r3 = Computer( &mult, 6, 7);
r4 = Computer( &divs, 6, 7);

printf("%.2f\n", r1);
printf("%.2f\n", r2);
printf("%.2f\n", r3);
printf("%.2f\n", r4);
}