1 files changed, 50 insertions, 1 deletions
diff --git a/src/2022/day6/aoc.cpp b/src/2022/day6/aoc.cpp
index 6c53b41..6fd3159 100644
--- a/src/2022/day6/aoc.cpp
+++ b/src/2022/day6/aoc.cpp
@@ -1,8 +1,57 @@
 #include "aoc.h"
 
 namespace aoc2022 {
+
+int next4(const char* p) {
+  char cs[4] = {0};
+  for(int i = 0; i < 4; i++) {
+    cs[i] = *(p + i);
+  }
+  if (cs[0] == cs[1]) return 1;
+  if (cs[0] == cs[2]) return 1;
+  if (cs[0] == cs[3]) return 1;
+  if (cs[1] == cs[2]) return 2;
+  if (cs[1] == cs[3]) return 2;
+  if (cs[2] == cs[3]) return 3;
+  return 0; 
+}
+
+int exam(int x, char cs[], int s) {
+  if (x == s) {
+    return 0;
+  }
+  for (int i = x + 1; i < s; i++) {
+    if (cs[x] == cs[i]) {
+      return x + 1;
+    }
+  }
+  return exam(x+1, cs, s);
+}
+
+int next14(const char* p) {
+  char cs[14] = {0};
+  for(int i = 0; i < 14; i++) {
+    cs[i] = *(p + i);
+  }
+  return exam(0, cs, 14);
+}
+
 std::pair<int,int> day6(line_view file) {
-  return {0,0};
+  const char *p0 = file.line;
+  int d0 = next4(p0);
+  while (d0 != 0) {
+    p0 += d0;
+    d0 = next4(p0);
+  }
+
+  const char *p1 = file.line;
+  int d1 = next14(p1);
+  while (d1 != 0) {
+    p1 += d1;
+    d1 = next14(p1);
+  }
+
+  return {p0 - file.line + 4 , p1 - file.line + 14};
 }
 
 }