Compilare: main.cpp: In function 'int main()': main.cpp:35:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<q.size();i+=2) fout<<q[i].first<<" "<<q[i].second<<" "; ~^~~~~~~~~ main.cpp:37:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<q.size();i+=2) fout<<q[i].first<<" "<<q[i].second<<" "; ~^~~~~~~~~ main.cpp:27:14: warning: 'Y' may be used uninitialized in this function [-Wmaybe-uninitialized] if(a[X][Y]) break; ~~~~~~^ main.cpp:27:14: warning: 'X' may be used uninitialized in this function [-Wmaybe-uninitialized]