Compilare: user.cpp: In function ‘void Dfs(int)’: user.cpp:68:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < V[a].size(); ++ j) ^ user.cpp:80:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < V[b].size(); ++ j) ^ user.cpp:88:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < V[x].size(); ++ j) ^ user.cpp: In function ‘void read()’: user.cpp:40:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("paznici3.in", "r", stdin); ^ user.cpp:41:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:45:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp: In function ‘void solve()’: user.cpp:105:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n", &z, &a, &b); ^ user.cpp: In function ‘void write()’: user.cpp:113:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("paznici3.out", "w", stdout); ^