Use OpenMP to parallelize day 22

Author: fwcd

day22/experiments/Makefile

@@ -1,8 +1,11 @@
+# We need Homebrew LLVM since Apple Clang doesn't support OpenMP
+CXX=/opt/homebrew/opt/llvm/bin/clang++
+
 .PHONY: all
 all: out/day22
 
 out:
 	mkdir -p $@
 
 out/day22: ./day22.cpp | out
-	$(CXX) $< -Ofast -std=c++11 -o $@
+	$(CXX) $< -ffast-math -fopenmp -O3 -std=c++11 -o $@

day22/experiments/day22.cpp

@@ -54,6 +54,7 @@ int score(std::vector<int> input, int x1, int x2, int x3, int x4) {
 int findBestScore(std::vector<int> input) {
   int bestScore = 0;
   int bound = 9;
+  #pragma omp parallel for
   for (int x1 = -bound; x1 <= bound; x1++) {
     for (int x2 = -bound; x2 <= bound; x2++) {
       std::cout << "Searching (" << x1 << ", " << x2 << ")" << std::endl;