C语言中如何调用文件中的自定义函数答:void main(){ int n1,n2;long a;long sum(int a,int b);long factorical(int n);printf("Enter n1 and n2:");scanf("%d,%d",&n1,&n2);a=sum(n1,n2);printf("a=%ld",a);getch();} long sum(int a,int b){ long c1,c2;c1=factorical(a);/*n1把值传递给a,并调用函数...