1 files changed, 30 insertions, 0 deletions
diff --git a/challenge-123/abigail/lua/ch-2.lua b/challenge-123/abigail/lua/ch-2.lua
new file mode 100644
index 0000000000..b379f3078a
--- /dev/null
+++ b/challenge-123/abigail/lua/ch-2.lua
@@ -0,0 +1,30 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-2.lua < input-file
+--
+
+local pat = "(-?%d+)";
+for _ = 2, 8 do
+    pat = pat .. "%s+(-?%d+)";
+end
+
+
+for line in io . lines () do
+    _, _, x1, y1, x2, y2, x3, y3, x4, y4 = line : find (pat)
+    local e1 = (x1 - x2) ^ 2 + (y1 - y2) ^ 2
+    local e2 = (x2 - x3) ^ 2 + (y2 - y3) ^ 2
+    local e3 = (x3 - x4) ^ 2 + (y3 - y4) ^ 2
+    local e4 = (x4 - x1) ^ 2 + (y4 - y1) ^ 2
+    local d1 = (x1 - x3) ^ 2 + (y1 - y3) ^ 2
+    local d2 = (x2 - x4) ^ 2 + (y2 - y4) ^ 2
+    if  e1 == e2 and e2 == e3 and e3 == e4 and d1 == d2 then
+        print (1)
+    else
+        print (0)
+    end
+end