1245. Sum of Special Numbers

Idea: Violent enumeration
code:

# include<iostream>
# include<cstring>
# include<cstdio>
# include<algorithm>
using namespace std;

int main()
{
    
    
    int n;
    cin >> n;
    int res = 0;
    for(int i = 1;i <= n;i++)
    {
    
    
        int x = i;
        while(x)
        {
    
    
            int t = x % 10;
            x /= 10;
            if(t == 2 || t == 0 || t == 1 || t == 9)
            {
    
    
                res += i;
                break;
            }
        }
    }
    cout << res << endl;
    
    return 0;
}