initial commit

2 files changed, 41 insertions, 0 deletions

diff --git a/2021/day7/07a.clj b/2021/day7/07a.clj
new file mode 100644
index 0000000..d9cb0f7
--- /dev/null
+++ b/2021/day7/07a.clj
@@ -0,0 +1,19 @@
+(ns day-7)
+
+(require '[clojure.string :as str])
+
+(defn totalDelta [xs dst]
+  (reduce + (map (fn [x] (Math/abs ^int (- x dst))) xs)))
+
+(defn calcIdealPos [xs start]
+  (def thisDelta (totalDelta xs start))
+  (def nextDelta (totalDelta xs (+ 1 start)))
+  (cond (> nextDelta thisDelta) start
+        :else (calcIdealDst xs (+ 1 start))))
+
+(def input (as-> (slurp "./input") x
+             (str/split x #",")
+             (map str/trim x)
+             (map #(. Integer parseInt %) x)))
+
+(totalDelta input (calcIdealPos input (apply min input)))
diff --git a/2021/day7/07b.clj b/2021/day7/07b.clj
new file mode 100644
index 0000000..9e248c8
--- /dev/null
+++ b/2021/day7/07b.clj
@@ -0,0 +1,22 @@
+(ns day-7)
+
+(require '[clojure.string :as str])
+
+(defn fuelCost [x]
+  (/ (* x (+ 1 x)) 2))
+
+(defn totalDelta [xs dst]
+  (reduce + (map (fn [x] (fuelCost (Math/abs ^int (- x dst)))) xs)))
+
+(defn calcIdealPos [xs start]
+  (def thisDelta (totalDelta xs start))
+  (def nextDelta (totalDelta xs (+ 1 start)))
+  (cond (> nextDelta thisDelta) start
+        :else (calcIdealDst xs (+ 1 start))))
+
+(def input (as-> (slurp "./input") x
+             (str/split x #",")
+             (map str/trim x)
+             (map #(. Integer parseInt %) x)))
+
+(totalDelta input (calcIdealPos input (apply min input)))