Compilare: user.cpp: In function ‘int main()’: user.cpp:42:22: warning: left operand of comma operator has no effect [-Wunused-value] {v,x=p.x+dl[k];v.y=p.y+dc[k]; ^ user.cpp:43:30: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if (L[v.x][v.y]=0) ^ cc1plus: warning: iteration 2u invokes undefined behavior [-Waggressive-loop-optimizations] user.cpp:41:9: note: containing loop for(k=1;k<=4;k++) ^