1 files changed, 8 insertions, 32 deletions
diff --git a/src/2017/day21/aoc.h b/src/2017/day21/aoc.h
index 1f743c2..4b2c464 100644
--- a/src/2017/day21/aoc.h
+++ b/src/2017/day21/aoc.h
@@ -20,18 +20,11 @@ struct square2 {
 
   std::vector<square2> flip() const noexcept {
     square2 s0;
-    s0.s[0] = s[1];
-    s0.s[1] = s[0];
-    s0.s[2] = s[3];
-    s0.s[3] = s[2];
-
-    square2 s1;
-    s1.s[0] = s[2];
-    s1.s[1] = s[3];
-    s1.s[2] = s[0];
-    s1.s[3] = s[1];
+    for (int i = 0; i < 4; i++) {
+      s0.s[i] = s[i] == '#' ? '.' : '#';
+    }
 
-    return {s0, s1};
+    return {s0};
   }
 
   std::vector<square2> rotate() const noexcept {
@@ -106,28 +99,11 @@ struct square3 {
 
   std::vector<square3> flip() const noexcept {
     square3 s0;
-    s0.s[0] = s[2];
-    s0.s[1] = s[1];
-    s0.s[2] = s[0];
-    s0.s[3] = s[5];
-    s0.s[4] = s[4];
-    s0.s[5] = s[3];
-    s0.s[6] = s[8];
-    s0.s[7] = s[7];
-    s0.s[8] = s[6];
-
-    square3 s1;
-    s1.s[0] = s[6];
-    s1.s[6] = s[0];
-    s1.s[3] = s[3];
-    s1.s[1] = s[7];
-    s1.s[7] = s[1];
-    s1.s[4] = s[4];
-    s1.s[2] = s[8];
-    s1.s[8] = s[2];
-    s1.s[5] = s[5];
+    for (int i = 0; i < 9; i++) {
+      s0.s[i] = s[i] == '#' ? '.' : '#';
+    }
 
-    return {s0, s1};
+    return {s0};
   }
 
   std::vector<square3> rotate() const noexcept {