Compilare: user.cpp: In function ‘int main()’: user.cpp:43:59: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;j>=i-d && 0<=j;--j) for(it1=0; it1<p[j].size(); ++it1) valid(p[j][it1]); ^ user.cpp:44:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(it2=0; it2<p[i].size(); ++it2) ++a[find(p[i][it2])]; ^ user.cpp:45:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(it2=0; it2<p[i].size(); ++it2) sol[p[i][it2]]=a[find(p[i][it2])]; ^