Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:19:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<from[x].size(); i++) ^ user.cpp: In function ‘void revdfs(int)’: user.cpp:34:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v[x].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:44:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ user.cpp:46:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&cost[i]); ^ user.cpp:50:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&NR); ^ user.cpp:54:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&a); ^