Compilare: user.cpp: In function ‘int cost(std::string, std::string)’: user.cpp:23:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = a.size() ; i < b.size() ; ++i) ^ user.cpp:26:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < a.size() ; ++i) ^ user.cpp: In function ‘int main()’: user.cpp:34:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dist.in" , "r" , stdin); ^ user.cpp:35:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dist.out" , "w" , stdout); ^ user.cpp:37:8: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(t); ^ user.cpp:54:8: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(t); ^ /tmp/cctsFP54.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.