From d66aaa10226d2ccc94749fcdb255fa2eb969d0ed Mon Sep 17 00:00:00 2001
From: Charles Cabergs <me@cacharle.xyz>
Date: Wed, 23 Jun 2021 14:49:04 +0200
Subject: problem 85 in julia

---
 julia/085-counting_rectangles.jl | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 julia/085-counting_rectangles.jl

(limited to 'julia')

diff --git a/julia/085-counting_rectangles.jl b/julia/085-counting_rectangles.jl
new file mode 100644
index 0000000..004cdbd
--- /dev/null
+++ b/julia/085-counting_rectangles.jl
@@ -0,0 +1,28 @@
+###
+# Counting rectangles
+# Problem 85
+#
+# By counting carefully it can be seen that a rectangular grid measuring 3 by 2 contains
+# eighteen rectangles:
+# Although there exists no rectangular grid that contains exactly two million rectangles,
+# find the area of the grid with the nearest solution.
+###
+
+
+# blackpenredpend: https://www.youtube.com/watch?v=Uq9OXC0Gzgw
+
+using Base.Iterators
+
+
+const TARGET_RECTANGLES = 2_000_000
+
+combinations_2(n) = (n * (n - 1)) / 2
+dist = Inf
+for width in countfrom(1), height in 1:width
+    count = combinations_2(width + 1) * combinations_2(height + 1)
+    global dist = min(dist, abs(TARGET_RECTANGLES - count))
+    if dist < 3  # I just tested a bunch of different threshold
+        println(width * height)
+        break
+    end
+end
-- 
cgit