Compilare: user.cpp: In function ‘int main()’: user.cpp:80:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < b.size(); ++j){ ^ user.cpp:56:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("desen.in", "r", stdin); ^ user.cpp:57:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("desen.out", "w", stdout); ^ user.cpp:58:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:61:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &A, &B); ^