Compilare: user.cpp: In function ‘int main()’: user.cpp:23:9: warning: unused variable ‘l1’ [-Wunused-variable] int l1 = strlen(s); ^ user.cpp:24:9: warning: unused variable ‘l2’ [-Wunused-variable] int l2 = strlen(ss); ^ user.cpp:19:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("readunare.in" , "r", stdin); ^ user.cpp:20:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("readunare.out" , "w", stdout); ^ user.cpp:21:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ user.cpp:22:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(ss + 1); ^ /tmp/ccDimRWn.o: In function `main': user.cpp:(.text.startup+0x55): warning: the `gets' function is dangerous and should not be used.