Compilare: main.cpp: In function 'int main()': main.cpp:4:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses] #define mask (1 << 8) -1 ~~~~~~~~~^~ main.cpp:19:40: note: in expansion of macro 'mask' ++cnt[(v[it&1][i]>>(it*8))&mask]; ^~~~ main.cpp:4:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses] #define mask (1 << 8) -1 ~~~~~~~~~^~ main.cpp:5:35: note: in expansion of macro 'mask' #define pos(x) (x >> (it * 8) ) & mask ^~~~ main.cpp:24:27: note: in expansion of macro 'pos' v[(it+1)&1][e[pos(v[it&1][i])]++]=v[it&1][i]; ^~~