Compilare: user.cpp: In function 'std::string solve()': user.cpp:29: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void read_data()': user.cpp:52: warning: format '%s' expects type 'char*', but argument 3 has type 'char (*)[10000010]' user.cpp:53: warning: format '%s' expects type 'char*', but argument 3 has type 'char (*)[10000010]' user.cpp:75: warning: format '%s' expects type 'char*', but argument 3 has type 'char (*)[10000010]' user.cpp: In function 'void solve_and_write()': user.cpp:117: warning: comparison between signed and unsigned integer expressions