Compilare: user.cpp: In function ‘void sub(int, int)’: user.cpp:13:3: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(x<=x2&&x1<x2)if(v[x+1][y]==0){v[x+1][y]=l; ^ user.cpp:21:7: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(x==x2&&y1<y2)if(v[x][y+1]==0){v[x][y+1]=l; ^ user.cpp:30:3: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(x>=x2&&x1>x2)if(v[x-1][y]==0){v[x-1][y]=l; ^ user.cpp:38:10: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(x==x2&&x1>y2)if(v[x][y-1]==0){v[x][y-1]=l; ^ user.cpp: In function ‘int main()’: user.cpp:57:7: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^