Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:10:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[x].size(); ++i) ^ user.cpp: In function ‘void dfs2(int)’: user.cpp:22:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < gtr[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:52:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < rez[i].size(); ++j) ^ user.cpp:31:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in", "r", stdin); ^ user.cpp:32:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out", "w", stdout); ^ user.cpp:34:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:37:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^