Compilare: user.cpp: In function ‘state dfs(board, state)’: user.cpp:56:32: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(r = check(b, 0,0, 1,1, 2,2)) ^ user.cpp:58:32: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(r = check(b, 0,2, 1,1, 2,0)) ^ user.cpp:61:33: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(r = check(b, i,0, i,1, i,2)) ^ user.cpp:63:38: warning: suggest parentheses around assignment used as truth value [-Wparentheses] else if(r = check(b, 0,i, 1,i, 2,i)) ^ user.cpp: In function ‘int main()’: user.cpp:100:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] b.v[0][i] = mp[v[i]]; ^ user.cpp:103:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] b.v[1][i] = mp[v[i]]; ^ user.cpp:106:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] b.v[2][i] = mp[v[i]]; ^ /tmp/cc2UqM2X.o: In function `main': user.cpp:(.text.startup+0x6a): warning: the `gets' function is dangerous and should not be used.