Compilare: user.cpp: In function ‘int main()’: user.cpp:21:26: warning: unused variable ‘cost’ [-Wunused-variable] int i, j, l, l1, l2, cost; ^ user.cpp:24:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("car.in", "r", stdin); ^ user.cpp:25:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("car.out", "w", stdout); ^ user.cpp:27:59: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d%d%d%d", &n, &m, &S.x, &S.y, &F.x, &F.y); ^ user.cpp:30:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &a [i][j]); ^