From 100b893f9ee67c8a26dfd038785b59bede7fcf5a Mon Sep 17 00:00:00 2001
From: roy <roybetsalel@gmail.com>
Date: Tue, 14 Jul 2026 10:15:08 +0300
Subject: Solved 2015 question 3.

---
 years/2015.cpp | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 100 insertions(+), 12 deletions(-)

(limited to 'years/2015.cpp')

diff --git a/years/2015.cpp b/years/2015.cpp
index 67fe1a6..b894d55 100644
--- a/years/2015.cpp
+++ b/years/2015.cpp
@@ -1,8 +1,28 @@
 #include "../aoc.h"
+#include <algorithm>
 #include <iostream>
+#include <set>
 #include <sstream>
 #include <vector>
 
+std::vector<std::string> splitstring(std::string input, char splitter) {
+  std::stringstream splitterstream(input);
+  std::string segment;
+  std::vector<std::string> splatstring;
+
+  while (std::getline(splitterstream, segment, splitter)) {
+    splatstring.push_back(segment);
+  }
+
+  return splatstring;
+}
+
+template <typename T>
+bool vectorcontains(const std::vector<std::tuple<T, T>> &v,
+                    const std::tuple<T, T> &x) {
+  return std::find(v.begin(), v.end(), x) != v.end();
+}
+
 int y2015_q01_p01(std::string instructions) {
   int floor = 0;
 
@@ -25,18 +45,6 @@ int y2015_q01_p02(std::string instructions) {
   return -1;
 }
 
-std::vector<std::string> splitstring(std::string input, char splitter) {
-  std::stringstream splitterstream(input);
-  std::string segment;
-  std::vector<std::string> splatstring;
-
-  while (std::getline(splitterstream, segment, splitter)) {
-    splatstring.push_back(segment);
-  }
-
-  return splatstring;
-}
-
 int y2015_q02_p01_instance(int l, int w, int h) {
   return std::min(l * w, std::min(l * h, h * w)) + 2 * l * w + 2 * l * h +
          2 * w * h;
@@ -79,3 +87,83 @@ int y2015_q02_p02() {
 
   return sum;
 }
+
+int y2015_q03_p01() {
+  std::string input;
+  getline(std::cin, input);
+
+  std::set<std::tuple<int, int>> board;
+  board.insert({0, 0});
+  int x, y;
+
+  for (const char &c : input) {
+    switch (c) {
+    case '>':
+      x++;
+      break;
+    case '<':
+      x--;
+      break;
+    case '^':
+      y++;
+      break;
+    case 'v':
+      y--;
+      break;
+    }
+    board.insert({x, y});
+  }
+
+  return static_cast<int>(board.size());
+}
+
+int y2015_q03_p02() {
+  std::string input;
+  std::cout << "Warning! This input might need to be hardcoded depending on "
+               "your terminal's input length limit.";
+  getline(std::cin, input);
+
+  std::set<std::tuple<int, int>> board;
+  board.insert({0, 0});
+  bool bot = false;
+  int x = 0, y = 0, x2 = 0, y2 = 0;
+
+  for (const char &c : input) {
+    if (bot) {
+      switch (c) {
+      case '>':
+        x2++;
+        break;
+      case '<':
+        x2--;
+        break;
+      case '^':
+        y2++;
+        break;
+      case 'v':
+        y2--;
+        break;
+      }
+      board.insert({x2, y2});
+    } else {
+      switch (c) {
+      case '>':
+        x++;
+        break;
+      case '<':
+        x--;
+        break;
+      case '^':
+        y++;
+        break;
+      case 'v':
+        y--;
+        break;
+      }
+      board.insert({x, y});
+    }
+    bot = !bot;
+  }
+
+  return static_cast<int>(board.size());
+}
-- 
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