m"K"=[1,2]
m"Q"=m"B"++m"R"
m"R"=[1,4,9]
m"B"=[2,8,18]
m"N"=[5]
m"P"=[2]
f[_]=[[]]
f l
=[(i
,j
):r
|(i
@(s
,t
),a
)<-l
,(j
@(u
,v
),_)<-l
%i
,r
<-f
$(j
,a
):l
%i
%j
,(s
-u
)^2+(t
-v
)^2`
elem`m a
]
bSJLIj1bMSwyXQptIlEiPW0iQiIrK20iUiIKbSJSIj1bMSw0LDldCm0iQiI9WzIsOCwxOF0KbSJOIj1bNV0KbSJQIj1bMl0KbCV4PVt6fHo8LWwsZnN0IHovPXhdCmZbX109W1tdXQpmIGw9WyhpLGopOnJ8KGlAKHMsdCksYSk8LWwsKGpAKHUsdiksXyk8LWwlaSxyPC1mJChqLGEpOmwlaSVqLChzLXUpXjIrKHQtdileMmBlbGVtYG0gYV0KIAptYWluID0gcmVhZExuID4+PSAobWFwTV8gcHJpbnQgLiBmKQ==
WygoMSwgMiksICZxdW90O0ImcXVvdDspLCAoKDIsIDIpLCAmcXVvdDtOJnF1b3Q7KSwgKCgzLCAxKSwgJnF1b3Q7USZxdW90OyksICgoMCwgMCksICZxdW90O0ImcXVvdDspXQ==
[((1, 2), "B"), ((2, 2), "N"), ((3, 1), "Q"), ((0, 0), "B")]
[((0,0),(2,2)),((3,1),(2,2)),((2,2),(1,2))]