单项选择题
A. f=0; for(i=1 ;i<=n;i+ +) f*=i; B. f=1; for(i=1;i<n;i+ +) f*=i; C. f=1; for(i=n;i>1;i+ +)f*=i; D. f=1; for(i=n;i>=2;i--)f*=i;
A) typedef struct int n; char c;REC; REC t1,t2; B) struct REC; int n; char c;; REC t1,t2; C) typedef struct REC; int n=0; char c='A'; t1,t2; D) stmct int n; char c; REC; REC t1,t2;