Compilare: main.cpp: In function 'int main()': main.cpp:45:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<strlen(sir); ++j) { ~^~~~~~~~~~~~ main.cpp:39:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rj.in","r",stdin); ^ main.cpp:40:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rj.out","w",stdout); ^