The qsort () function in C
void qsort function (void * base, so-phan-tu, kich-co, int (* compar) (const void *, const void *)) arranges an array.The function ldiv () in C
the div_t div function (long int numer, long int denom) divides the numerator numer to denom.The function atexit () in C
int atexit function (void (* func) (void)) calls function func when the program ends. you can register your end function (func function) wherever you like, but this function will