Compilare: user.cpp: In function ‘void solve()’: user.cpp:61:12: warning: unused variable ‘j’ [-Wunused-variable] int i, k, j; ^ user.cpp: In function ‘void readdata()’: user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("grazing.in", "r", stdin); ^ user.cpp:16:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("grazing.out", "w", stdout); ^ user.cpp:17:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^