day8 part1

1 files changed, 42 insertions, 0 deletions

diff --git a/src/2015/day8/aoc.cpp b/src/2015/day8/aoc.cpp
index 1c33c66..feae5dc 100644
--- a/src/2015/day8/aoc.cpp
+++ b/src/2015/day8/aoc.cpp
@@ -1,5 +1,47 @@
 #include "aoc.h"
 
 namespace aoc2015 {
+// a -> 1
+// \\ -> 1
+// \" -> 1
+// \xXX -> 1
+int count_day8(line_view lv) {
+  int total = 0;
+  const char* p1 = lv.line;
+  const char* p2 = lv.line + lv.length;
+  const char* p = p1;
+  while (p != p2) {
+    if (*p != '\\' || p == p2 - 1) {
+      total += 1;
+      p++;
+      continue;
+    } else {
+      if (*(p + 1) == '\\' || *(p + 1) == '"') {
+        total += 1;
+        p += 2;
+        continue;
+      }
+      if (*(p + 1) == 'x') {
+        total += 1;
+        p += 4;
+        continue;
+      }
+      total += 1;
+      p++;
+    }
+  }
+  return total;
+}
 
+int day8(line_view file) {
+  int t1 = 0;
+  int t2 = 0;
+  per_line(file, [&t1, &t2](line_view lv) {
+    t1 += lv.length - 1;
+    t2 += count_day8({lv.line + 1, lv.line + lv.length - 2});
+    return true;
+  });
+  return t1 - t2;
 }
+
+} // namespace aoc2015