3

lib/include/aocpp/Coord.hpp

@@ -40,6 +40,8 @@ auto CW(Coord) -> Coord;
 /// Rotate counter-clockwise
 auto CCW(Coord) -> Coord;
 
+auto Norm1(Coord) -> std::int64_t;
+
 /// Add two coordinates pairwise
 auto operator+(Coord, Coord) -> Coord;
 

lib/src/Coord.cpp

@@ -1,5 +1,7 @@
 #include <aocpp/Coord.hpp>
 
+#include <cstdlib>
+
 namespace aocpp {
 
 auto Draw(std::ostream & out, std::map<Coord, std::int64_t> image) -> void {
@@ -65,6 +67,10 @@ auto CCW(Coord c) -> Coord {
   return c;
 }
 
+auto Norm1(Coord c) -> std::int64_t {
+  return std::abs(c.x) + std::abs(c.y);
+}
+
 auto operator+(Coord a, Coord b) -> Coord {
   return {a.x + b.x, a.y + b.y};
 }