Compilare: user.cpp: In function ‘int main()’: user.cpp:23: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:24: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:51: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result user.cpp:27: warning: ‘xs’ may be used uninitialized in this function user.cpp:27: warning: ‘ys’ may be used uninitialized in this function user.cpp:58: warning: ‘dir’ may be used uninitialized in this function /tmp/ccXcoy6g.o: In function `main': user.cpp:(.text+0x166): warning: the `gets' function is dangerous and should not be used.