Compilare: user.cpp: In function ‘void solc(int)’: user.cpp:53:31: 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:18:38: 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:19:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:20:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^ user.cpp:23:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &vix, &viy); ^ user.cpp: In function ‘void write()’: user.cpp:77:40: 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); ^