Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:28:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<g[x].size();++i) ^ user.cpp: In function ‘void dfst(int)’: user.cpp:39:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<gt[x].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:68:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<ctc[i].size();++j) ^ user.cpp: In function ‘void load()’: user.cpp:15:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:18:32: 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 ‘int main()’: user.cpp:47:32: 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:48:34: 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); ^