Compilare: user.cpp: In function ‘void solc(int)’: user.cpp:56:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < V[a].size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:24:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pachete.in", "r", stdin); ^ user.cpp:25:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:26:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp:29:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &vi.x, &vi.y); ^ user.cpp: In function ‘void write()’: user.cpp:80:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pachete.out", "w", stdout); ^