Compilare: user.cpp: In function ‘void afisare()’: user.cpp:52:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<=C.size()-1; i++) ^ user.cpp: In function ‘int main()’: user.cpp:20:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.in", "rt", stdin); ^ user.cpp:21:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.out", "wt", stdout); ^ user.cpp: In function ‘void citire()’: user.cpp:32:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:35:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &u, &v); ^