Compilare: user.cpp: In function ‘int main()’: user.cpp:22: warning: unused variable ‘sum2’ 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:22: warning: ‘s2f’ may be used uninitialized in this function user.cpp:22: warning: ‘s1f’ may be used uninitialized in this function