1 files changed, 20 insertions, 0 deletions
diff --git a/others/other/hcn.py b/others/other/hcn.py
new file mode 100755
index 0000000..6b2fa2b
--- /dev/null
+++ b/others/other/hcn.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+from collections import deque
+
+
+def not_square(A, B, C):
+    """Return False is ABC is a square angle, True otherwise."""
+    return (B[0]-A[0])*(B[0]-C[0]) + (B[1]-A[1])*(B[1]-C[1])
+
+
+def parallelogram_last_point(A, B, C):
+    """Return the (x, y) coordinates of the point D of the parallelogram
+    ABCD.
+    """
+    return A[0] - B[0] + C[0], A[1] - B[1] + C[1]
+
+
+with open('hcn.inp') as fi, open('hcn.out', 'w') as fo:
+    d = deque(tuple(map(int, line.split())) for line in fi.readlines())
+    while not_square(*d): d.rotate()
+    print(*parallelogram_last_point(*d), file=fo)