Just one big program question for freshly baked interview questions

This afternoon, I went to the legendary ** interview. I had two questions and asked n! The number of 0 at the end of the result, for example, 18! = The number of zeros at the end of 6402373705728000 is 3.ProgramImplementation and complexity.

BelowCode:

Typedef unsigned _ int64 ty; ty getn (ty n) {If (n = 1) {return 1;} return N * getn (n-1 );} ty countzero (TY m) {If (M % 10! = 0) {return 0;} return 1 + countzero (M/10);} ty getzero (ty I) {return countzero (getn (I ));} ty getfuckzero (ty I) {return I/5;} int _ tmain (INT argc, _ tchar * argv []) {ty n = 18; printf ("% LlU! = % LlU-> % LlU \ n ", N, getn (N), getzero (N), getfuckzero (n); Return 0 ;}