Compilare: user.cpp: In function ‘int main()’: user.cpp:49:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < strlen(x); j ++) { ^ user.cpp:14:54: 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:15:56: 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); ^