Compilare: user.cpp: In function ‘void dfs(int, int, int, int)’: user.cpp:34:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i1 = 0; i1 < V[n1].size(); i1++) ^ user.cpp:38:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i2 = 0; i2 < V[n2].size(); i2++) ^ user.cpp: In function ‘void rez()’: user.cpp:54:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < V[i].size(); j++) ^ user.cpp: In function ‘void cit()’: user.cpp:14:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &N); ^ user.cpp:17:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &x, &y); ^ user.cpp:21:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("\n"); ^ user.cpp:22:30: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets (S, nmax<<1, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:72:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("arbpal.in", "r", stdin); ^ user.cpp:73:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("arbpal.out", "w", stdout); ^