TrainingCamp
#include <string>
#include <vector>
using namespace std;
class TrainingCamp{public:
vector <string> determineSolvers( vector <string> attendance, vector <string> problemTopics )
{
int N = (int)attendance.size();
int M = (int)attendance[0].size();
int K = (int)problemTopics.size();
vector<string> ans( N, string(K,'X') );
for ( int i=0; i<N; i++ )
for ( int j=0; j<K; j++ )
for ( int k=0; k<M; k++ )
if ( problemTopics[j][k]=='X' && attendance[i][k]=='-' )
ans[i][j] = '-';
return ans;
}};