错误代码：

#include<iostream>
#include<vector>
#include<unordered_map>
using namespace std;

int main() {
    unordered_map<int, string> map = {
        {0, "zero"}, {1, "one"}, {2, "two"}, {3, "three"}, {4, "four"},
        {5, "five"}, {6, "six"}, {7, "seven"}, {8, "eight"}, {9, "nine"}
    };
    int num;
    cin >> num;
    int sum = 0;
    // Handle the case where num is 0
    if (num == 0) {
        sum = 0;
    }
    else {
        while (num > 0) {
            sum += num % 10;
            num /= 10;
        }
    }
    // Handle the case where sum is 0 (for input num = 0)
    if (sum == 0) {
        cout << map[0] << endl;
        return 0;
    }
    vector<int> v;
    while (sum > 0) {
        int r = sum % 10;
        v.push_back(r);
        sum /= 10;
    }
    int length = v.size();
    for (int i = length - 1; i >= 0; i--) {
        cout << map[v[i]];
        if (i != 0) {
            cout << " ";
        }
    }
    return 0;
}

数字越界

正确代码（用字符串处理）：

#include<iostream>
#include<vector>
#include<unordered_map>
using namespace std;

int main() {
    unordered_map<int, string> map = {
        {0, "zero"}, {1, "one"}, {2, "two"}, {3, "three"}, {4, "four"},
        {5, "five"}, {6, "six"}, {7, "seven"}, {8, "eight"}, {9, "nine"}
    };
    string num;
    cin >> num;
    int sum = 0;

    // Calculate the sum of digits
    for (char c : num) {
        sum += c - '0';
    }

    // If sum is zero, we handle it directly
    if (sum == 0) {
        cout << map[0] << endl;
        return 0;
    }

    vector<int> digits;
    while (sum > 0) {
        digits.push_back(sum % 10);
        sum /= 10;
    }

    // Output the digits in English
    for (int i = digits.size() - 1; i >= 0; i--) {
        cout << map[digits[i]];
        if (i != 0) {
            cout << " ";
        }
    }
    cout << endl;

    return 0;
}