Data update

Task/Cut-a-rectangle/Pluto/cut-a-rectangle.pluto

@@ -0,0 +1,68 @@
+require "table2"
+local fmt = require "fmt"
+
+local count <const> = {0}
+local dir <const> = {{0, -1}, {-1, 0}, {0, 1}, {1, 0}}
+
+local function walk(y, x, h, w, grid, len, nxt)
+    if y == 0 or y == h or x == 0 or x == w then
+        count[1] += 2
+        return
+    end
+    local t = y * (w + 1) + x
+    grid[t + 1] += 1
+    grid[len - t + 1] += 1
+    for i = 1, 4 do
+        if grid[t + nxt[i] + 1] == 0 then
+            walk(y + dir[i][1], x + dir[i][2], h, w, grid, len, nxt)
+        end
+    end
+    grid[t + 1] -= 1
+    grid[len - t + 1] -= 1
+end
+
+local function cutrectangle(hh, ww, recur)
+    local h, w
+    if hh % 2 != 0 then
+        h, w = ww, hh
+    else
+        h, w = hh, ww
+    end
+    if h % 2 != 0 then
+        return 0
+    elseif w == 1 then
+        return 1
+    elseif w == 2 then
+        return h
+    elseif h == 2 then
+        return w
+    end
+    local cy = h // 2
+    local cx = w // 2
+    local len = (h + 1) * (w + 1)
+    local grid = table.rep(len, 0)
+    len -= 1
+    local nxt = {-1, -w - 1, 1, w + 1}
+    if recur then count[1] = 0 end
+    for x = cx + 1, w - 1 do
+        local t = cy * (w + 1) + x
+        grid[t + 1] = 1
+        grid[len - t + 1] = 1
+        walk(cy - 1, x, h, w, grid, len, nxt)
+    end
+    count[1] += 1
+    if h == w then
+        count[1] *= 2
+    elseif w % 2 == 0 and recur then
+        cutrectangle(w, h, false)
+    end
+    return count[1]
+end
+
+for y = 1, 10 do
+    for x = 1, y do
+        if x % 2 == 0 or y % 2 == 0 then
+            fmt.print($"%2d x %2d: %d", y, x, cutrectangle(y, x, true))
+        end
+    end
+end