Compilare: user.cpp: In function ‘void prefix(std::string)’: user.cpp:18: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void match(std::string, std::string)’: user.cpp:33: warning: comparison between signed and unsigned integer expressions user.cpp:41: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:61: warning: comparison between signed and unsigned integer expressions user.cpp:64: warning: comparison between signed and unsigned integer expressions user.cpp:67: warning: comparison between signed and unsigned integer expressions user.cpp:82: warning: comparison between signed and unsigned integer expressions user.cpp:86: warning: comparison between signed and unsigned integer expressions user.cpp:94: warning: comparison between signed and unsigned integer expressions user.cpp:100: warning: comparison between signed and unsigned integer expressions user.cpp:114: warning: comparison between signed and unsigned integer expressions user.cpp:51: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:52: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result