阶乘统计3 TYVJ P1142 题解

program P1142; var n,i,ans:int64; begin assign(input,'P1142.in'); reset(input); assign(output,'P1142.out'); rewrite(output); ans:=0; readln(n); i:=5; while n div i<>0 do begin inc(ans,n div i); i:=i*5; end; writeln(ans); close(input); close(output); end.