Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:21:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<a[nod].size(); j++) { ^ user.cpp: In function ‘int main()’: user.cpp:49:24: warning: unused variable ‘j’ [-Wunused-variable] int i, m, n, x, y, j; ^ user.cpp:50:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &n, &m); ^ user.cpp:52:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &x, &y); ^