Compilare: user.cpp: In function ‘void bfs()’: user.cpp:23:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < G[aux].size(); ++ i) ^ user.cpp: In function ‘int main()’: user.cpp:43:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 1 ; i <= m ; ++ i) ^ user.cpp:40:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sate.in", "r", stdin); ^ user.cpp:41:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sate.out", "w", stdout); ^ user.cpp:42:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &n, &m, &x, &y); ^ user.cpp:45:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &a, &b, &c); ^