Compilare: user.cpp: In function ‘void schimba()’: user.cpp:14: warning: NULL used in arithmetic user.cpp:19: warning: NULL used in arithmetic user.cpp:13: warning: unused variable ‘len’ user.cpp: In function ‘int main()’: user.cpp:87: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:88: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:89: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result user.cpp:90: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:92: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result /tmp/ccaqxYeJ.o: In function `main': user.cpp:(.text+0x1b3): warning: the `gets' function is dangerous and should not be used.