Compilare: user.cpp: In function ‘int main()’: user.cpp:20:35: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(xs[i]>xs[j] || xs[i]==xs[j] && ys[i]>=ys[j]){ ^ user.cpp:32:35: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(xt[i]>xt[j] || xt[i]==xt[j] && yt[i]>=yt[j]){ ^ user.cpp:6:6: warning: unused variable ‘a’ [-Wunused-variable] int a,b; ^ user.cpp:6:8: warning: unused variable ‘b’ [-Wunused-variable] int a,b; ^