Compilare: user.cpp: In function ‘int main()’: user.cpp:78:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < sol[i].size(); ++j) fprintf(fout,"%d ",sol[i][j]); ^ user.cpp:66:30: 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:69:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d",&x,&y); ^