填空题

下面程序的功能是：对字符串从小到大进行排序并输出，请填空。 #include"string.h" #include"stdio.h" sort(char *a[],int n) { int i,j; char *p; for(j=1;j＜=n-1;j++) for(i=0;i＜n-j;i++) if(______)＞0) { p=a[i]; a[i]=a[i+1]; a[i+1]=p;} } main() {int i; char *book[]={"itisme","itisyou","howareyou","fine","goodnight","goodbye"}; sort(______); for(i=0;i＜6;i++) printf("%s\n",book[i]); }