#include<stdio.h>int fun(int a,int b){if(a>b)return a+b;elsereturn a-b;}void main(){int x=3,y=8,z=6,r;r=fun(fun(x,y),2*z);printf("%d\n",r);}这种的怎么做啊?C语言的,好难 求大佬解答