Compilare: user.cpp: In destructor ‘tractor::~tractor()’: user.cpp:30: warning: comparison between signed and unsigned integer expressions user.cpp: In member function ‘void tractor::generate_children()’: user.cpp:54: warning: comparison between signed and unsigned integer expressions user.cpp:60: warning: comparison between signed and unsigned integer expressions user.cpp:61: warning: comparison between signed and unsigned integer expressions user.cpp:67: warning: comparison between signed and unsigned integer expressions user.cpp:68: warning: comparison between signed and unsigned integer expressions user.cpp:69: warning: comparison between signed and unsigned integer expressions user.cpp:70: warning: comparison between signed and unsigned integer expressions user.cpp: In member function ‘int tractor::find(int, int)’: user.cpp:102: warning: comparison between signed and unsigned integer expressions user.cpp:105: warning: comparison between signed and unsigned integer expressions user.cpp: In member function ‘void tractor::search(int, int (*)[16])’: user.cpp:157: warning: comparison between signed and unsigned integer expressions user.cpp:160: warning: comparison between signed and unsigned integer expressions user.cpp:163: warning: comparison between signed and unsigned integer expressions user.cpp: In member function ‘void tractor::clear_M()’: user.cpp:174: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:187: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:188: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:194: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:199: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:204: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result