# include int fun (int x) { int p; if(x==1) return 2; else
# include int fun (int x) { int p; if(x==1) return 2; else p=x-fun (x-2); rerurnm p; } void main () { printf(“%d\n”,fun (9));}
【正确答案】:6
【题目解析】:主函数中调用fun(9)函数,fun()函数中是一个递归调用的过程:fun (9)=9- fun (7)= 9-(7-fun (5))=9-(7-(5-fun (3)))=9-(7-(5-(3-fun (1))))=9-(7-(5-(3-2)))=9-(7-(5-1))=9-(7-4)=9-3=6