expresie1.cpp: In function 'int main()': expresie1.cpp:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result expresie1.cpp:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result expresie1.cpp:12: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/cc45VWAC.o: In function `main': expresie1.cpp:(.text+0x5b): warning: the `gets' function is dangerous and should not be used.