题解 | #[NOIP2008]ISBN号码#

#include <cmath>
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

int main() {
    string ISBN;
    cin >> ISBN;
    int sum = 0, less;
    int o = 1;
    int check;
    
    for (int i = 0; i < ISBN.length(); i++) {
        if (ISBN[i] >= '0' && ISBN[i] <= '9' && o<=9) {
            sum += (ISBN[i] - '0') * o;
            o++;
        }
    }
    less = sum%11;
    if(ISBN.back()!= 'X')
    {
    check = ISBN.back()-'0';
    if (less==check)
    {
      cout<<"Right";
    }
    else{
    if (less == 10) {
        ISBN.back() = 'X';
    } else {
        ISBN.back() = '0' + less;
    }
    cout<<ISBN;
    }
    }
    else{
      check = 10;
      if (less==check)
    {
      cout<<"Right";
    }
    else{
    if (less == 10) {
        ISBN.back() = 'X';
    } else {
        ISBN.back() = '0' + less;
    }
    cout<<ISBN;
    }
    }

    
}

感觉有点麻烦了，输入字符串遍历，处理数字字符，累加计算后，检查，注意是不是X