编写一个C++程序，输入一个数字支，并写出与该数字相等的单词。例如，数字52.43应写成 FIFTY TWO and 43/100

以下是一个简单的C++程序，实现了输入数字支并输出对应的英文单词和小数部分的功能：

#include <iostream>
using namespace std;

string digit_to_word(int digit) {
    // 数字转换为英文单词的函数
    string words[] = {"ZERO", "ONE", "TWO", "THREE", "FOUR", "FIVE", "SIX", "SEVEN", "EIGHT", "NINE"};
    return words[digit];
}

string tens_to_word(int tens, int ones) {
    // 十位数字和个位数字转换为英文单词的函数
    string words[] = {"", "", "TWENTY", "THIRTY", "FORTY", "FIFTY", "SIXTY", "SEVENTY", "EIGHTY", "NINETY"};
    if (tens == 1) {
        string words[] = {"TEN", "ELEVEN", "TWELVE", "THIRTEEN", "FOURTEEN", "FIFTEEN", "SIXTEEN", "SEVENTEEN", "EIGHTEEN", "NINETEEN"};
        return words[ones];
    } else {
        return words[tens] + " " + digit_to_word(ones);
    }
}

int main() {
    double num;
    cout << "请输入一个数字支：";
    cin >> num;

    // 获取整数部分和小数部分
    int integer_part = (int)num;
    int decimal_part = (int)((num - integer_part) * 100);

    // 转换整数部分为英文单词
    string words = "";
    if (integer_part == 0) {
        words = "ZERO";
    } else {
        int billions = integer_part / 1000000000;
        int millions = (integer_part % 1000000000) / 1000000;
        int thousands = (integer_part % 1000000) / 1000;
        int hundreds = integer_part % 1000;
        if (billions > 0) {
            words += digit_to_word(billions) + " BILLION ";
        }
        if (millions > 0) {
            words += tens_to_word(millions / 100, millions % 100) + " MILLION ";
        }
        if (thousands > 0) {
            words += tens_to_word(thousands / 100, thousands % 100) + " THOUSAND ";
        }
        if (hundreds > 0) {
            words += tens_to_word(hundreds / 100, hundreds % 100);
        }
    }

    // 转换小数部分为英文单词
    string decimal_words = "";
    if (decimal_part > 0) {
        decimal_words = "AND " + to_string(decimal_part) + "/100";
    }

    // 输出结果
    cout << words << decimal_words << endl;
    return 0;
}

这个程序首先读入一个double类型的数字，然后将整数部分和小数部分分离出来，分别转换为对应的英文单词。对于整数部分的转换，我们先将数字按照“亿、百万、千”的单位进行分割，然后分别转换每个部分，最后拼接起来即可。对于小数部分，我们直接将小数部分转换为“分数”的形式输出即可。