题解 | #密码验证合格程序#

package main

import (
    "fmt"
    "bufio"
    "os"
)

func main() {
	reader := bufio.NewScanner(os.Stdin)
	for reader.Scan() {
		s := reader.Text()
		if IsValid(s) {
			fmt.Println("OK")
		} else {
			fmt.Println("NG")
		}
	}
}

func IsValid(s string) bool {
	if len(s) <= 8 {
		return false
	}

	m := map[rune]bool{}
	for _, v := range s {
		switch {
		case v >= 'A' && v <= 'Z':
			m['A'] = true
		case v >= 'a' && v <= 'z':
			m['a'] = true
		case v >= '0' && v <= '9':
			m['0'] = true
		default:
			if v != ' ' && v != '\n' {
				m['@'] = true
			}
		}
	}
	if len(m) < 3 {
		return false
	}

	md := make(map[string]bool)
	for i := 0; i < len(s)-2; i++ {
		if _, ok := md[s[i:i+3]]; !ok {
			md[s[i:i+3]] = true
		} else {
			return false
		}
	}
	return true
}