Compilare: user.cpp: In function ‘int main()’: user.cpp:24:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("abc2.in", "r", stdin); ^ user.cpp:25:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("abc2.out", "w", stdout); ^ user.cpp:30:41: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(text + 1), n = strlen(text + 1); ^ user.cpp:32:35: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1), m = strlen(s + 1); ^ user.cpp:45:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ /tmp/ccRm9ww5.o: In function `main': user.cpp:(.text.startup+0x5f): warning: the `gets' function is dangerous and should not be used.