代码

#include <iostream>
#include <string>
using namespace std;
int main() {
string isbn;
cin >> isbn;
string nums = "";
for (char c : isbn) {
if (isdigit(c)) {
nums += c;
}
}
int total = 0;
for (int i = 0; i < 9; i++) {
total += (nums[i] - '0') * (i + 1);
}
int remainder = total % 11;
char calculated_check_digit;
if (remainder == 10) {
calculated_check_digit = 'X';
} else {
calculated_check_digit = remainder + '0';
}
if (calculated_check_digit == isbn.back()) {
cout << "Right" << endl;
} else {
isbn.back() = calculated_check_digit;
cout << isbn << endl;
}
return 0;
}