rem: int low=0,high=flist->count;
add: int low=0,high=flist->count-1;
context: int flist_find(struct file_list *flist,struct file_struct *f){  int low=0,high=flist->count;  while (low != high) {    int mid = (low+high)/2;    int ret = file_compare(&flist->files[mid],f);    if (ret == 0) return mid;    if (ret > 0)       high=mid;    else      low=mid+1;  }  if (file_compare(&flist->files[low],f) == 0)    return low;  return -1;}