2 files changed, 72 insertions, 1 deletions
diff --git a/src/2016/day8/aoc.cpp b/src/2016/day8/aoc.cpp
index 55f4247..fd56a51 100644
--- a/src/2016/day8/aoc.cpp
+++ b/src/2016/day8/aoc.cpp
@@ -2,4 +2,10 @@
 
 namespace aoc2016 {
 
+int day8(line_view file) {
+  grid<5, 6> g;
+  g.set(2, 2);
+  return 0;
 }
+
+} // namespace aoc2016
diff --git a/src/2016/day8/aoc.h b/src/2016/day8/aoc.h
index 95823fe..d92a8f7 100644
--- a/src/2016/day8/aoc.h
+++ b/src/2016/day8/aoc.h
@@ -3,4 +3,69 @@
 
 namespace aoc2016 {
 
-}
+template <size_t W, size_t H>
+struct grid {
+  char cells[W * H] = {0};
+
+  void print() {
+    for (size_t i = 0; i < ARRAY_SIZE(cells); i++) {
+      printf("%d", cells[i]);
+      if (i % W == W - 1) {
+        printf("\n");
+      }
+    }
+    printf("\n");
+  }
+
+  void set(int x, int y) {
+    for (int j = 0; j < y; j++) {
+      for (int i = 0; i < x; i++) {
+        cell(i, j) = 1;
+      }
+    }
+  }
+
+  char& cell(int x, int y) { return cells[y * W + x]; }
+  char& prev_h(int x, int y) {
+    int n = x == 0 ? W - 1 : x - 1;
+    return cell(n, y);
+  }
+
+  void rotate_h(int y) {
+    char last = cell(W - 1, y);
+    for (int x = W - 1; x > 0; x--) {
+      cell(x, y) = prev_h(x, y);
+    }
+    cell(0, y) = last;
+  }
+
+  void rotate_h(int y, int t) {
+    t %= W;
+    while (t-- > 0) {
+      rotate_h(y);
+    }
+  }
+
+  char& prev_v(int x, int y) {
+    int n = y == 0 ? H - 1 : y - 1;
+    return cell(x, n);
+  }
+
+  void rotate_v(int x) {
+    char last = cell(x, H - 1);
+    for (int y = H - 1; y > 0; y--) {
+      cell(x, y) = prev_v(x, y);
+    }
+    cell(x, 0) = last;
+  }
+
+  void rotate_v(int x, int t) {
+    t %= H;
+    while (t-- > 0) {
+      rotate_v(x);
+    }
+  }
+};
+
+int day8(line_view);
+} // namespace aoc2016