Compilare: user.cpp: In function ‘int buildGrapgh()’: user.cpp:68:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:88:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<L[i].size();j++){ ~^~~~~~~~~~~~ user.cpp:72:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d%d%d",&n,&m,&x,&y); ^ user.cpp:75:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&b[i]); ^