如何用C++开发进制转换器 位运算和数值处理技巧

#include <iostream>
#include <string>
#include <algorithm>
#include <cmath>

// 将字符转换为对应的数值（例如 'A' -> 10）
int charToInt(char c) {
    if (c >= '0' && c <= '9') return c - '0';
    if (c >= 'A' && c <= 'Z') return c - 'A' + 10;
    if (c >= 'a' && c <= 'z') return c - 'a' + 10;
    return -1; // 无效字符
}

// 将数值转换为对应的字符（例如 10 -> 'A'）
char intToChar(int n) {
    if (n >= 0 && n <= 9) return n + '0';
    if (n >= 10 && n <= 35) return n - 10 + 'A';
    return '\0'; // 无效数值
}

// 字符串转换为十进制
long long stringToDecimal(const std::string& num, int base) {
    long long decimalValue = 0;
    long long power = 1;
    for (int i = num.length() - 1; i >= 0; --i) {
        int digit = charToInt(num[i]);
        if (digit < 0 || digit >= base) {
            std::cerr << "Invalid digit in input number." << std::endl;
            return -1; // 错误
        }
        decimalValue += digit * power;
        power *= base;
    }
    return decimalValue;
}

// 十进制转换为字符串
std::string decimalToString(long long decimalValue, int base) {
    if (decimalValue == 0) return "0";
    std::string result = "";
    while (decimalValue > 0) {
        int remainder = decimalValue % base;
        result += intToChar(remainder);
        decimalValue /= base;
    }
    std::reverse(result.begin(), result.end());
    return result;
}

int main() {
    std::string number;
    int sourceBase, targetBase;

    std::cout << "Enter the number: ";
    std::cin >> number;
    std::cout << "Enter the source base (2-36): ";
    std::cin >> sourceBase;
    std::cout << "Enter the target base (2-36): ";
    std::cin >> targetBase;

    if (sourceBase < 2 || sourceBase > 36 || targetBase < 2 || targetBase > 36) {
        std::cerr << "Invalid base. Base must be between 2 and 36." << std::endl;
        return 1;
    }

    long long decimalValue = stringToDecimal(number, sourceBase);
    if (decimalValue == -1) {
        return 1;
    }

    std::string result = decimalToString(decimalValue, targetBase);
    std::cout << "Result: " << result << std::endl;

    return 0;
}

std::string stringAddition(const std::string& num1, const std::string& num2) {
    std::string result = "";
    int carry = 0;
    int i = num1.length() - 1, j = num2.length() - 1;

    while (i >= 0 || j >= 0 || carry) {
        int digit1 = (i >= 0) ? (num1[i] - '0') : 0;
        int digit2 = (j >= 0) ? (num2[j] - '0') : 0;

        int sum = digit1 + digit2 + carry;
        carry = sum / 10;
        result += std::to_string(sum % 10);

        i--;
        j--;
    }

    std::reverse(result.begin(), result.end());
    return result;
}

bool isValidInput(const std::string& number, int base) {
    for (char c : number) {
        int digit = charToInt(c);
        if (digit < 0 || digit >= base) {
            return false; // 无效字符
        }
    }
    return true;
}

#include <iostream>
#include <iomanip>
#include <bitset>

void printFloatBinary(float f) {
    // 使用联合体来访问浮点数的二进制表示
    union {
        float f;
        int i;
    } data;
    data.f = f;

    // 使用 bitset 来输出二进制表示
    std::bitset<sizeof(float) * 8> binary(data.i);
    std::cout << binary.to_string() << std::endl;
}

int main() {
    float num = 3.14159;
    std::cout << "Binary representation of " << num << " is: ";
    printFloatBinary(num);
    return 0;
}