2021 day8 part1

1 files changed, 29 insertions, 0 deletions

diff --git a/src/2021/day8/aoc.cpp b/src/2021/day8/aoc.cpp
index 7a3c895..9f95991 100644
--- a/src/2021/day8/aoc.cpp
+++ b/src/2021/day8/aoc.cpp
@@ -1,5 +1,34 @@
 #include "aoc.h"
+#include <algorithm>
 
 namespace aoc2021 {
 
+static void get_length(const char** pp, int* d) {
+  const char* p = *pp;
+  *d = 0;
+  while (*p >= 'a' && *p <= 'g') {
+    *d += 1;
+    p++;
+  }
+  *pp = p;
 }
+
+int day8(line_view file) {
+  // int digits[] = {6, 2, 5, 5, 4, 5, 6, 3, 7, 6};
+  int total{0};
+  int ls[4] = {0};
+  per_line(file, [&ls, &total](line_view lv) {
+    const char* p = lv.contains("|") + 2;
+    int index{0};
+    while (p < lv.line + lv.length) {
+      get_length(&p, &ls[index]);
+      total += int(ls[index] == 2 || ls[index] == 3 || ls[index] == 4 || ls[index] == 7);
+      index++;
+      p++;
+    }
+    return true;
+  });
+  return total;
+}
+
+} // namespace aoc2021