Compilare: main.cpp: In function 'void Displaying()': main.cpp:58:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<ctc[i].size();++j)fprintf(g,"%d ",ctc[i][j]); ~^~~~~~~~~~~~~~ main.cpp: In function 'void Read()': main.cpp:13:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&N,&M); ^ main.cpp:16:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&X,&Y); ^