Compilare: user.cpp: In function ‘int main()’: user.cpp:23:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(M.size() >= d + 1) { ~~~~~~~~~^~~~~~~~ user.cpp:15:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("slidingwindow.in", "r", stdin); ^ user.cpp:16:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("slidingwindow.out", "w", stdout); ^ user.cpp:19:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &d); ^ user.cpp:22:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^