2022 day5

1 files changed, 62 insertions, 0 deletions

diff --git a/src/2020/day9/aoc.cpp b/src/2020/day9/aoc.cpp
index 849bad9..c7a826f 100644
--- a/src/2020/day9/aoc.cpp
+++ b/src/2020/day9/aoc.cpp
@@ -1,5 +1,67 @@
 #include "aoc.h"
+#include <set>
 
 namespace aoc2020 {
+static int numbers[1000] = {0};
+
+static int get_number(const char* p) {
+  int d{0};
+  while (*p >= '0' && *p <= '9') {
+    d = d * 10 + *p - '0';
+    p++;
+  }
+  return d;
+}
+
+bool check25(int i, int* weak) {
+  std::set<int> si;
+  for (int x = i - 25; x < i; x++) {
+    si.insert(numbers[x]);
+  }
+  for (int x = i - 25; x < i; x++) {
+    int y = numbers[i] - numbers[x];
+    if (si.find(y) != si.end()) {
+      return true;
+    }
+  }
+
+  *weak = numbers[i];
+  return false;
+}
+
+bool check_contiguous(int i, int* end, int target) {
+  return false;
+}
+
+static void minmax(int x, int y, int* min, int* max) {
+
+}
+
+std::pair<int, int> day9(line_view file) {
+  int i{0};
+  per_line(file, [&i](line_view lv){
+    numbers[i++] = get_number(lv.line);
+    return true;
+  });
+
+  int weak{0};
+  int pos{0};
+  for (int i = 25; i < 1000; i++) {
+    if (!check25(i, &weak)) {
+      pos = i;
+      break;
+    }
+  }
+
+  int e{0};
+  int min{INT32_MAX}, max{INT32_MIN};
+  for (int i = 0; i < pos; i++) {
+    if (check_contiguous(i, &e, weak)) {
+      minmax(i, e, &min, &max);
+    }
+  }
+
+  return {weak, min + max};
+}
 
 }