1 files changed, 16 insertions, 2 deletions
diff --git a/src/2020/day9/aoc.cpp b/src/2020/day9/aoc.cpp
index c7a826f..10ba789 100644
--- a/src/2020/day9/aoc.cpp
+++ b/src/2020/day9/aoc.cpp
@@ -30,11 +30,25 @@ bool check25(int i, int* weak) {
 }
 
 bool check_contiguous(int i, int* end, int target) {
-  return false;
+  if (target == 0) {
+    *end = i;
+    return true;
+  }
+  if (target < 0) {
+    return false;
+  }
+  return check_contiguous(i + 1, end, target - numbers[i]);
 }
 
 static void minmax(int x, int y, int* min, int* max) {
-
+  for(int i = x; i < y; i++) {
+    if (*min > numbers[i]) {
+        *min = numbers[i];
+    }
+    if (*max < numbers[i]) {
+        *max = numbers[i];
+    }
+  }
 }
 
 std::pair<int, int> day9(line_view file) {