http://projecteuler.net/problem=37 [Answer:748317]

 

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
    const int N = 1000000;
    const int D = 1000;
    vector<bool> bPrime( N, true );
    bPrime[0] = false;
    bPrime[1] = false;
    for ( int i = 2; i < D; ++i )
    {
        if ( bPrime[i] )
        {
            for ( int j = i + i; j < N; j += i )
            {
                bPrime[j] = false;
            }
        }
    }

    int count = 0;
    int result = 0;
    for ( int n = 10; n < N; ++n )
    {
        if ( bPrime[n] )
        {
            int mod = 10;
            while ( mod <= n )
            {
                if ( !bPrime[n/mod] || !bPrime[n%mod] )
                {
                    break;
                }
                mod *= 10;
            }
            if ( mod > n )
            {
                result += n;
                count++;
                if ( count == 11 )
                {
                    break;
                }
            }
        }
    }

    cout << result << endl;

    return 0;
}