leetcode-go/easy/172.go

package main

import (
	"math"
)

// ???
func trailingZeroesOld(n int) int {
	cnt := 0
	for i := 5; i <= n; i += 5 {
		cnt += int(math.Log(float64(i)) / math.Log(5))
	}
	return cnt
}

func trailingZeroes(n int) int {
	var res int
	for n > 0 {
		n /= 5
		res += n
	}
	return res
}

// func main() {
// 	fmt.Println(trailingZeroes(3))
// 	fmt.Println(trailingZeroes(7))
// 	fmt.Println(trailingZeroes(10))
// 	fmt.Println(trailingZeroes(100))
// 	fmt.Println(int(math.Log10(float64(125)) / math.Log10(5)))
// }