2025 day 2 part 1

2025/2.txt

@@ -0,0 +1 @@
+11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,446443-446449,38593856-38593862,565653-565659,824824821-824824827,2121212118-2121212124

2025/aoc.cpp

@@ -3,6 +3,7 @@
 
 #include "aoc.hpp"
 #include "day1.hpp"
+#include "day2.hpp"
 
 int main(int argc, char** argv)
 {

2025/aoc.hpp

@@ -12,6 +12,11 @@ struct FileFragment
     std::string Data;
 };
 
+inline std::pair<FileFragment, FileFragment> SplitToken(std::string del)
+{
+
+}
+
 class File
 {
 public:

2025/day2.hpp

@@ -0,0 +1,116 @@
+#include "aoc.hpp"
+
+#include <algorithm>
+#include <unordered_map>
+
+class Day02 : public AOCDay
+{
+public:
+    Day02() {}
+    ~Day02() {}
+    int Day() override {return 2;}
+
+    int PartOne(File& f) override
+    {
+        f.SplitBy(",");
+
+        uint64_t res = 0;
+
+        // Range of ID's (11-22)
+        for (auto range : f.TokensForLine(0))
+        {
+            int dash = range.Data.find('-', 0);
+
+            uint64_t a = std::stoll(range.Data.substr(0, dash));
+            uint64_t b = std::stoll(range.Data.substr(dash + 1));
+
+            for (uint64_t i = a; i <= b; i++)
+            {
+                // Convert number back into string
+                std::string current = std::to_string(i);
+                // import 'is-odd' lol
+                if (current.length() & 1) continue;
+
+                int mid = current.length() / 2;
+
+                uint64_t l = std::stoll(current.substr(0, mid));
+                uint64_t r = std::stoll(current.substr(mid));
+
+                if (l == r)
+                {
+                    res += i;
+                }
+            }
+        }
+
+        std::cout << "The answer doesn't fit in int : "<< res << std::endl;
+        return res;
+    }
+
+    int PartTwo(File& f) override
+    {
+        f.SplitBy(",");
+
+        uint64_t res = 0;
+
+        for (auto range : f.TokensForLine(0))
+        {
+            int dash = range.Data.find('-', 0);
+
+            uint64_t a = std::stoll(range.Data.substr(0, dash));
+            uint64_t b = std::stoll(range.Data.substr(dash + 1));
+
+            for (uint64_t i = a; i <= b; i++)
+            {
+                std::string current = std::to_string(i);
+                int n = current.length();
+
+                bool invalid = false;
+
+                // Try every possible substring start (i)
+                for (int start = 0; start < n && !invalid; start++)
+                {
+                    std::string accum;
+
+                    // Build accum char-by-char
+                    for (int end = start; end < n && !invalid; end++)
+                    {
+                        accum.push_back(current[end]);
+
+                        int len = accum.length();
+                        int remaining = n - start;
+
+                        // Now check if repeats match
+                        bool matches = true;
+
+                        for (int rep = 0; rep < remaining / len; rep++)
+                        {
+                            if (current.compare(start + rep * len, len, accum) != 0)
+                            {
+                                matches = false;
+                                break;
+                            }
+                        }
+
+                        // Must be at least two repeats
+                        if (matches && remaining / len >= 2)
+                        {
+                            invalid = true;
+                            break;
+                        }
+                    }
+                }
+
+            if (invalid)
+                res += i;
+        }
+    }
+
+
+        std::cout << "The answer doesn't fit in int : "<< res << std::endl;
+        return res;
+    }
+};
+
+ADD_AOC_DAY(Day02);
+