Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:16:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < g[nod].size(); i++) { ~~^~~~~~~~~~~~~~~ user.cpp: In function ‘void dfsT(int, int)’: user.cpp:26:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < gt[nod].size(); i++) { ~~^~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:76:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < sol[i].size(); j ++) { ~~^~~~~~~~~~~~~~~ user.cpp:34:32: 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:35:34: 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); ^ user.cpp:40:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:42:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^