5/13課輔-身分證字號檢驗

#include <iostream>
#include <string>
#include <cctype>
using namespace std;
int main()
{
    string s, num = "0123456789";
    bool check = true;
    cout << "nplease input ID:";
    while (getline(cin, s))
    {
        if (s.size() != 10)
        {
            cout << "ID應為10碼\n";
            check = false;
        }
        if (isalpha(s[0]))
        {
            if (s.find_first_not_of(num,1) != string::npos)
            {
                cout << "後九碼應為數字\n";
                check = false;
            }
        }
        else
        {
            cout << "第一碼應為英文字母\n";
            check = false;
        }

        if (check)
        {
            cout << "is ID\n";
        }
        else
        {
            cout << "not ID\nplease input ID:";
            check=true;
            continue;
        }


        int letter_number[] = { 10, 11, 12, 13, 14, 15, 16, 17, 34, 18, 19, 20, 21, 22, 35, 23, 24, 25, 26, 27, 28, 29, 32, 30, 31, 33 };
        if (islower(s[0]))
        {
            s[0] = toupper(s[0]);
        }
        int sum = letter_number[(s[0] - 'A')] / 10 + letter_number[(s[0] - 'A')] % 10 * 9;
        for (int i = 1; i < 9; i++)
        {
            sum += (s[i] - '0')*(9 - i);
        }
        int checknum = (10 - (sum % 10)) % 10;
        if (checknum == (s[9] - '0'))
        {
            cout << "true ID\n";
        }
        else
        {
            cout << "fake ID\n";
        }
        cout << "please input ID:";
    }
}