题解 | #字符个数统计#

package main

import "fmt"

func main() {
	var inputStr string
	if _, err := fmt.Scan(&inputStr); err != nil {
		fmt.Printf("input err:%v\n", err)
		return
	}

	var charMap = make(map[string]bool)
	for _, char := range inputStr {
		if _, ok := charMap[string(char)]; ok {
			continue
		}

		charMap[string(char)] = true
	}

	fmt.Printf("%d\n", len(charMap))
}