1 files changed, 47 insertions, 1 deletions
diff --git a/src/2018/day4/aoc.h b/src/2018/day4/aoc.h
index 4bfdbf3..563f0c0 100644
--- a/src/2018/day4/aoc.h
+++ b/src/2018/day4/aoc.h
@@ -3,4 +3,50 @@
 
 namespace aoc2018 {
 
-}
+struct guard {
+  int id = 0;
+  struct {
+    int month;
+    int day;
+    int hour;
+    int minute;
+  } timestamp = {0, 0, 0, 0};
+  enum {
+    on,
+    off,
+  } status = off;
+
+  int offtime[60] = {0};
+  int ontime[60] = {0};
+
+  void get_number(const char** pp, int* d) {
+    const char* p = *pp;
+    while (*p >= '0' && *p <= '9') {
+      *d = *d * 10 + *p - '0';
+      p++;
+    }
+    *pp = p;
+  }
+
+  guard(line_view lv) {
+    int* ds[] = {&timestamp.month, &timestamp.day, &timestamp.hour, &timestamp.minute, &id};
+    const char* p = lv.line + 6;
+    int i{0};
+    while (p < lv.line + lv.length) {
+      if (*p >= '0' && *p <= '9') {
+        get_number(&p, ds[i++]);
+        if (i == 4 && *(p + 2) == 'w') {
+          status = on;
+        }
+      }
+      p++;
+    }
+    if (id > 0) {
+      status = on;
+    }
+  };
+};
+
+int day4(line_view);
+
+} // namespace aoc2018