Compilare: user.cpp: In function ‘int main()’: user.cpp:73:71: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘const char*’ [-Wformat=] if ( hashin [ nr2 ] == hashin [ nr10 ] ) printf ("%d\n" , "0" ) ; ^ user.cpp:75:38: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘const char*’ [-Wformat=] printf ("%d\n" , "1" ) ; ^ user.cpp:17:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("twosets.in" , "r" , stdin ) ; ^ user.cpp:18:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("twosets.out" , "w" , stdout ) ; ^ user.cpp:19:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d" , &t ) ; ^ user.cpp:23:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets( s ) ; ^ user.cpp:50:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets( s1 ) ; ^ /tmp/cciIJCVq.o: In function `main': user.cpp:(.text.startup+0x94): warning: the `gets' function is dangerous and should not be used.