Compilare: main.cpp: In function 'bool cmp(P, P)': main.cpp:13:43: warning: suggest parentheses around '&&' within '||' [-Wparentheses] bool cmp(P a, P b){if(a.x>b.x || a.x==b.x && a.y>b.y)return 0;return 1;} ~~~~~~~~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:18:21: warning: unused variable 'b' [-Wunused-variable] int i,j,k,kk,n,m,a,b,dM[]={-1,0,1,0}; ^