Compilare: user.cpp: In function ‘int main()’: user.cpp:33:9: warning: unused variable ‘d’ [-Wunused-variable] int d[20004],o=0; ^ user.cpp:33:18: warning: unused variable ‘o’ [-Wunused-variable] int d[20004],o=0; ^ user.cpp:34:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxd.in","r",stdin); ^ user.cpp:35:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxd.out","w",stdout); ^ user.cpp:38:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^