Compilare: main.cpp: In function 'bool Check(config)': main.cpp:52:57: warning: suggest parentheses around '&&' within '||' [-Wparentheses] if (x.a[i] != x.a[j] && (Up(x, i, j, false) && Down(x, i, j, true) || Up(x, i, j, true) && Down(x, i, j, false))) ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:88:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < next.m.size(); ++i) ~~^~~~~~~~~~~~~~~