Compilare: user.cpp: In function ‘int main()’: user.cpp:53:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); ++i) for(int j=0; j<v.size(); ++j) if(is(v[i],v[j])!=mp(-1,-1)) { ^ user.cpp:53:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); ++i) for(int j=0; j<v.size(); ++j) if(is(v[i],v[j])!=mp(-1,-1)) { ^ user.cpp:62:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); ++i) for(int j=i+1; j<v.size(); ++j) if(!ma[i][j]) ^ user.cpp:62:57: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); ++i) for(int j=i+1; j<v.size(); ++j) if(!ma[i][j]) ^ user.cpp:63:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0; k<gr[i].size(); ++k) for(int l=k+1; l<gr[i].size(); ++l) { ^ user.cpp:63:67: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0; k<gr[i].size(); ++k) for(int l=k+1; l<gr[i].size(); ++l) { ^ user.cpp:60:7: warning: unused variable ‘r’ [-Wunused-variable] int r=0; ^