Compilare: user.cpp: In function ‘void Read()’: user.cpp:64:18: warning: unused variable ‘j’ [-Wunused-variable] int i, x, y, j; ^ user.cpp: In function ‘void Solve()’: user.cpp:85:9: warning: unused variable ‘x’ [-Wunused-variable] int x, y; ^ user.cpp:85:12: warning: unused variable ‘y’ [-Wunused-variable] int x, y; ^ user.cpp: In function ‘void Next()’: user.cpp:57:34: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] std::fread(r, 1, MAXR, f); ^