题解 | #密码强度等级#

解题思路：
依次判断条件并将结果存入总分数score中，由于rust中的char类型的is_ascii_digit()、is_ascii_uppercase()、is_ascii_lowercase()、is_ascii_punctuation() 四个函数可以分别用来判断数字、大小写和字符，所以就偷懒采用而不判ascii码了。

以下代码虽然行数较多，但是顺序阅读就会发现使用了较多的match表达式，逻辑较为简单。

use std::io::{self, *};

fn main() {
    let stdin = io::stdin();
    for line in stdin.lock().lines() {
        let ll = line.unwrap();
        let ll = ll.trim();
        let mut score = 0u8;
        score += match ll.len() {//长度
            0..=4 => 5,
            5..=7 => 10,
            _ => 25,
        };

        let (mut has_digit,mut has_up ,mut has_low,mut has_punc,mut has_more_dig,mut has_more_punc) = (false,false,false,false,false,false);
        for i in ll.chars() {
            if i.is_ascii_digit() {
                if !has_digit {
                    has_digit = true;   
                }else {
                    has_more_dig = true;
                    continue;
                }
            }else if i.is_ascii_uppercase() {
                if !has_up {
                    has_up = true;   
                }else {
                    continue;
                }
            }else if i.is_ascii_lowercase() {
                if !has_low {
                    has_low = true;   
                }else {
                    continue;
                }
            }else if i.is_ascii_punctuation() {
                if !has_punc {
                    has_punc = true;   
                }else {
                    has_more_punc = true;
                    continue;
                }
            }
        }
        score += match (has_low,has_up) {//字母
            (false,false) => 0,
            (true,true) => 20,
            _ => 10,
        };
        score += match (has_digit,has_more_dig) {//数字
            (false,false) => 0,
            (true,true) => 20,
            _ => 10,
        };
        score += match (has_punc,has_more_punc) {//符号
            (false,false) => 0,
            (true,true) => 25,
            _ => 10,
        };
        score += match (has_digit,has_up,has_low,has_punc) {//奖励
            (true,true,true,true) => 5,
            (true,true,false,true) | (true,false,true,true) => 3,
            (true,true,_,false) | (true,_,true,false) => 2,
            _ => 0,
        };
        println!("{}",match score {
            0..=24 => "VERY_WEAK",
            25..=49 => "WEAK",
            50..=59 => "AVERAGE",
            60..=69 => "STRONG",
            70..=79 => "VERY_STRONG",
            80..=89 => "SECURE",
            _ => "VERY_SECURE",
        })
    }
}