From f3f4b456ab7e5333de102d54e820708c16179491 Mon Sep 17 00:00:00 2001
From: Jesse McDonald <nybble41@gmail.com>
Date: Sat, 5 Sep 2015 12:21:18 -0500
Subject: [PATCH] Add solution for problem 63.

---
 Problem063.hs | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 Problem063.hs

diff --git a/Problem063.hs b/Problem063.hs
new file mode 100644
index 0000000..fad5c3f
--- /dev/null
+++ b/Problem063.hs
@@ -0,0 +1,6 @@
+-- How many n-digit positive integers exist which are also an nth power?
+import Data.List (nub)
+
+-- If x >= 10 then x^n >= 10^n and thus has more than n digits.
+-- If n >= 22 then 9^n < 10^(n-1) and thus has fewer than n digits.
+main = print $ length $ nub [ x^n | n <- [1..21], x <- [1..9], x^n >= 10^(n-1) ]