Compilare: user.cpp: In function 'void readdata()': user.cpp:41: warning: format '%s' expects type 'char*', but argument 2 has type 'char (*)[23]' user.cpp: In function 'void solve()': user.cpp:52: warning: comparison between signed and unsigned integer expressions user.cpp:58: warning: comparison between signed and unsigned integer expressions user.cpp:62: warning: comparison between signed and unsigned integer expressions user.cpp:49: warning: unused variable 'val'