Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:43:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[X].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:73:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("northrend.in","r",stdin); ^ user.cpp:74:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("northrend.out","w",stdout); ^ user.cpp:75:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &S); ^ user.cpp:77:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &X, &Y, &C); ^