if (c < w - 1 && (state->lines[i] & R || state->lines[i+1] & L))
memset(board + cell + 1, '-', cw - 1);
if (r < h - 1 && (state->lines[i] & D || state->lines[i+w] & U))
if (c < w - 1 && (state->lines[i] & R || state->lines[i+1] & L))
memset(board + cell + 1, '-', cw - 1);
if (r < h - 1 && (state->lines[i] & D || state->lines[i+w] & U))