一道C语言题,# include int fun (int n,int *s){int f1,f2;if (n==1||n==2) *s=1;else {fun(n-1,&f1); /* fun(5,&f1) fun(4,&f1) fun(3,&f1) fun(2,&f1) */fun(n-2,&f2); /* fun(4,&f2) fun(2,&f2) */*s=f1+f2;}}main(){int x;fun(6,&x);printf ("\n%d\n",x);}输