在本文中，我将解决 Perl Weekly Challenge #287 中的两个挑战：加强弱密码和验证数字。我将为这两项任务提供解决方案，展示 Perl 和 Go 中的实现。

目录

1. 加强弱密码
2. 验证数字
3. 结论

加强弱密码

第一个任务是确定使密码更安全所需的最少更改次数。强密码的标准是：

1. 至少有 6 个字符。
2. 至少包含1个小写字母、1个大写字母、1个数字。
3. 不包含三个连续相同的字符。

示例

• 输入：“a”→输出：5
• 输入：“aB2”→输出：3
• 输入：“PaaSW0rd”→输出：0
• 输入：“Paaasw0rd”→输出：1
• 输入：“aaaaa”→输出：2

解决方案

Perl 实现

#!/usr/bin/perl
use strict;
use warnings;
use List::Util 'max';

# Function to count groups of three or more repeating characters
sub count_repeats {
    my ($str) = @_;
    my $repeats = 0;

    # Find repeating characters and count the required changes
    while ($str =~ /(.)\1{2,}/g) {
        $repeats  = int(length($&) / 3);
    }

    return $repeats;
}

# Function to calculate the minimum steps to create a strong password
sub minimum_steps_to_strong_password {
    my ($str) = @_;
    my $length = length($str);

    # Check if the password contains the required character types
    my $has_lower = $str =~ /[a-z]/;
    my $has_upper = $str =~ /[A-Z]/;
    my $has_digit = $str =~ /\d/;

    # Calculate the number of types needed
    my $types_needed = !$has_lower   !$has_upper   !$has_digit;
    my $repeats = count_repeats($str);

    # Return the minimum steps based on the length of the password
    return ($length 




  
  
  Perl 实现的测试




use strict;
use warnings;
use Test::More;
require "./ch-1.pl";

my @tests = (
    ["a", 5],
    ["aB2", 3],
    ["PaaSW0rd", 0],
    ["Paaasw0rd", 1],
    ["aaaaa", 2],
);

foreach my $test (@tests) {
    my ($input, $expected) = @$test;
    my $result = minimum_steps_to_strong_password($input);
    is($result, $expected, "Input: '$input'");
}

done_testing();





  
  
  实施




package main

import (
    "regexp"
)

func countRepeats(password string) int {
    repeats := 0
    count := 1

    for i := 1; i  b {
        return a
    }
    return b
}





  
  
  Go 实现的测试




package main

import (
    "testing"
)

func TestMinimumStepsToStrongPassword(t *testing.T) {
    tests := []struct {
        password string
        expected int
    }{
        {"a", 5},
        {"aB2", 3},
        {"PaaSW0rd", 0},
        {"Paaasw0rd", 1},
        {"aaaaa", 2},
    }

    for _, test := range tests {
        result := minimumStepsToStrongPassword(test.password)
        if result != test.expected {
            t.Errorf("For password '%s', expected %d but got %d", test.password, test.expected, result)
        }
    }
}








  
  
  验证数字


第二个任务涉及验证数字。目标是确定给定的字符串是否代表有效的数字。有效数字的标准是：


整数（可选后跟指数符号）。
十进制数（可选后跟指数表示法）。
整数可以选择带有符号（- 或 ），后跟数字。



  
  
  示例

• 输入：“1”→输出：true
• 输入：“a”→输出：false
• 输入： ”。” → 输出：假
• 输入：“1.2e4.2”→输出：false
• 输入：“-1”。 → 输出：真
• 输入：“1E-8”→输出：true
• 输入：“.44”→输出：true

解决方案

Perl 实现

#!/usr/bin/perl
use strict;
use warnings;

sub is_valid_number {
    my ($str) = @_;

    # Regex for valid numbers
    my $regex = qr{
        ^            # Start of the string
        [ -]?        # Optional sign
        (?:          # Start of the number group
            \d       # Integer: at least one digit
            (?:      # Start of the optional decimal part
                \.   # Decimal point
                \d*  # Followed by zero or more digits
            )?       # Group is optional
            |        # or
            \.       # Just a decimal point
            \d       # Followed by one or more digits
        )            # End of the number group
        (?:          # Start of the optional exponent group
            [eE]     # 'e' or 'E'
            [ -]?    # Optional sign
            \d       # Followed by one or more digits
        )?           # Exponent is optional
        $            # End of the string
    }x;

    # Return 1 for valid, 0 for invalid
    return $str =~ $regex ? 1 : 0;
}

1;

Perl 实现的测试

#!/usr/bin/perl
use strict;
use warnings;
use Test::More;

require './ch-2.pl';

# Define test cases
my @test_cases = (
    ["1", 1, 'Valid integer'],
    ["a", 0, 'Invalid input'],
    [".", 0, 'Single dot'],
    ["1.2e4.2", 0, 'Invalid exponent'],
    ["-1.", 1, 'Valid decimal'],
    [" 1E-8", 1, 'Valid scientific notation'],
    [".44", 1, 'Valid decimal starting with dot'],
);

# Loop through test cases and run tests
foreach my $case (@test_cases) {
    my $result = is_valid_number($case->[0]);
    is($result, $case->[1], $case->[2]);
}

done_testing();

实施

package main

import (
    "regexp"
)

// isValidNumber checks if the given string is a valid number.
func isValidNumber(str string) bool {
    regex := `^[ -]?((\d (\.\d*)?)|(\.\d ))([eE][ -]?\d )?$`
    matched, _ := regexp.MatchString(regex, str)
    return matched
}

Go 实现的测试

package main

import (
    "testing"
)

func TestIsValidNumber(t *testing.T) {
    testCases := []struct {
        input    string
        expected bool
    }{
        {"1", true},
        {"a", false},
        {".", false},
        {"1.2e4.2", false},
        {"-1.", true},
        {" 1E-8", true},
        {".44", true},
    }

    for _, tc := range testCases {
        result := isValidNumber(tc.input)
        if result != tc.expected {
            t.Errorf("isValidNumber(%q) = %v; expected %v", tc.input, result, tc.expected)
        }
    }
}

结论

这些解决方案提供了评估密码强度和验证数字正确性的有效方法。这两项任务的完整代码可在 GitHub 上找到。