) get "input.ivy"

sample = 5 5 rho 3 0 3 7 3 2 5 5 1 2 6 5 3 3 2 3 3 5 4 9 3 5 3 9 0

########
"part 1"

op visible r =
    r = -1, r
    r = transp max\ transp r
    r = r > -1 flip r
    1 drop r

op vis2 m = (visible m) or (flip visible flip m)
op vis4 m = (vis2 m) or (transp vis2 transp m)

sample
+/, vis4 sample
+/, vis4 input


##########
"\npart 2"

op empty v = 0 == rho v

# count how many elements at the start of v are less than x
op x shorter v =
    empty v: 0
    +/ (and\ x > v)

# returns 1 if any v[i] blocks x
op x blocked v =
    empty v: 0
    or/ x <= v

op x viewDistance v = (x blocked v) + x shorter v

op p score A =
    x = p[1]
    y = p[2]
    e = A[y;x]
    row = A[y]
    col = A[;x]
    n = 1
    n = n * e viewDistance flip (x-1) take row
    n = n * e viewDistance x drop row
    n = n * e viewDistance flip (y-1) take col
    n = n * e viewDistance y drop col
    n

op i loopY A =
    x = i score A
    i[2] >= (rho A)[2]: x
    x , (i + 0 1) loopY A

op i loopX A =
    x = i loopY A
    i[1] >= (rho A)[1]: x
    x , (i + 1 0) loopX A

op solve A = max/ 1 1 loopX A

sample
solve sample
solve input