C++密码生成器如何将数字、大小写字母随机打乱混合输出？

现有代码问题 #

你当前的写法是按顺序分别循环输出数字、小写字母、大写字母，会导致所有同类型字符连续排列，无法满足随机混合、避免同类型连续的需求。

修改思路 #

• 首先增加输入合法性校验，确保三类字符数量总和等于你设定的密码总长度
• 先把生成的所有符合数量要求的字符存入临时容器，而非直接输出
• 对容器内的字符做随机打乱
• 增加连续同类型检测逻辑，若出现连续同类字符就重新打乱，直到满足规则
• 最后输出符合要求的密码

修改后完整代码 #

#include <iostream>
#include <ctime>
#include <vector>
#include <algorithm>
#include <cctype>
using namespace std;

const char num[] = "0123456789";
const char lower_alp[] = "abcdefghijklmnopqrstuvwxyz";
const char higher_alp[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
int sizeofnum = sizeof(num) - 1;
int sizeoflower_alp = sizeof(lower_alp) - 1;
int sizeofhigher_alp = sizeof(higher_alp) - 1;

int main()
{
    int password_length = 0, nums, loweralp, higheralp;
    cout << "Enter password length: ";
    cin >> password_length;
    cout << "How many lower alphabet symbols do you want in the password:";
    cin >> loweralp;
    cout << "How many higher alphabet symbols do you want in the password:";
    cin >> higheralp;
    cout << "How many numbers do you want in the password:";
    cin >> nums;
    
    // 输入合法性校验
    if (nums + loweralp + higheralp != password_length) {
        cout << "Error: The sum of three types of characters is not equal to the password length!" << endl;
        return 1;
    }
    
    srand(time(NULL));
    vector<char> pwd_container;
    
    // 生成对应数量的各类字符存入容器
    for (int i = 0; i < nums; i++) {
        pwd_container.push_back(num[rand() % sizeofnum]);
    }
    for (int la = 0; la < loweralp; la++) {
        pwd_container.push_back(lower_alp[rand() % sizeoflower_alp]);
    }
    for (int ha = 0; ha < higheralp; ha++) {
        pwd_container.push_back(higher_alp[rand() % sizeofhigher_alp]);
    }
    
    // 打乱并校验连续同类型
    bool is_valid = false;
    while (!is_valid) {
        random_shuffle(pwd_container.begin(), pwd_container.end());
        is_valid = true;
        for (int i = 1; i < pwd_container.size(); i++) {
            // 判断前后字符是否为同类型
            bool prev_num = isdigit(pwd_container[i-1]);
            bool prev_lower = islower(pwd_container[i-1]);
            bool curr_num = isdigit(pwd_container[i]);
            bool curr_lower = islower(pwd_container[i]);
            
            if ((prev_num && curr_num) || (prev_lower && curr_lower) || (!prev_num && !prev_lower && !curr_num && !curr_lower)) {
                is_valid = false;
                break;
            }
        }
    }
    
    // 输出最终密码
    for (char c : pwd_container) {
        cout << c;
    }
    cout << endl;
    
    return 0;
}

补充说明 #

如果某一类字符的数量远超过其他两类，比如10位密码里要求8个数字，逻辑上不可能做到没有连续同类型字符，程序会进入死循环，你可以根据需求增加最大重试次数的限制，避免这种情况。

内容的提问来源于stack exchange，提问作者averagestudent