> if(It != string_find_iterator()) cout << "(" << i << ", " << j << ") : " << (*It) << endl;

Modify this line to (*It) ==> (*It++)

if(It != string_find_iterator()) cout << "(" << i << ", " << j << ") : " << (*It++) << endl;

And output would be

$ ./a.exe
(0, 0) : ab
(0, 1) : cd
(1, 0) :
(1, 1) :
(2, 0) : xy
(2, 1) : z

Thank you,

NitiN

( NITIN DOT MOTGI AT GMAIL DOT COM )