Compilare: user.cpp: In function ‘int main()’: user.cpp:48:9: warning: unused variable ‘ok’ [-Wunused-variable] int ok = 0, Ans; ^ user.cpp:48:17: warning: unused variable ‘Ans’ [-Wunused-variable] int ok = 0, Ans; ^ user.cpp:31:54: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("infinitepatternmatching.in", "r", stdin); ^ user.cpp:32:56: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("infinitepatternmatching.out", "w", stdout); ^ user.cpp:43:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a + 1); ^ /tmp/cc3w1vYK.o: In function `main': user.cpp:(.text.startup+0xca): warning: the `gets' function is dangerous and should not be used.