bac.cpp: In function 'int transf(char*)': bac.cpp:17: warning: no return statement in function returning non-void bac.cpp: In function 'int main()': bac.cpp:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result bac.cpp:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result bac.cpp:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result bac.cpp:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result bac.cpp:39: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result bac.cpp:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result bac.cpp:47: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/cczSDcOR.o: In function `main': bac.cpp:(.text+0x168): warning: the `gets' function is dangerous and should not be used.