Compilare: user.cpp: In function ‘int main()’: user.cpp:25:122: warning: operation on ‘mat[(ve[i].coord::x + q)][(ve[i].coord::y + w)]’ may be undefined [-Wsequence-point] mat[ve[i].x-q][ve[i].y+w]=mat[ve[i].x-q][ve[i].y-w]=mat[ve[i].x+q][ve[i].y+w]=mat[ve[i].x+q][ve[i].y+w]=1; ^ user.cpp:28:122: warning: operation on ‘mat[(ve[i].coord::x + w)][(ve[i].coord::y - q)]’ may be undefined [-Wsequence-point] mat[ve[i].x+w][ve[i].y+q]=mat[ve[i].x-w][ve[i].y+q]=mat[ve[i].x+w][ve[i].y-q]=mat[ve[i].x+w][ve[i].y-q]=1; ^