Compilare: user.cpp:11:1: warning: ‘typedef’ was ignored in this declaration [enabled by default] }; ^ user.cpp: In function ‘bool sum_cmp(sum, sum)’: user.cpp:18:47: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] return (a.val < b.val || (a.val == b.val) && (a.x < b.x) || (a.val == b.val && a.x == b.x && a.y < b.y)); ^ user.cpp: In function ‘int main()’: user.cpp:58:37: warning: unused variable ‘val’ [-Wunused-variable] int x = a[i].x, y = a[i].y, val = a[i].val; ^