From c432d3f381384f0a07f29dd417dcd30cb227db0d Mon Sep 17 00:00:00 2001
From: Marcus Penate <marcus.penate@ellenbytech.com>
Date: Wed, 7 Dec 2022 09:07:06 -0500
Subject: [PATCH] Day 12

---
 Day 12/part1.cpp | 72 +++++++++++++++++++++++++++++++++++++++++++
 Day 12/part2.cpp | 80 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 152 insertions(+)
 create mode 100644 Day 12/part1.cpp
 create mode 100644 Day 12/part2.cpp

diff --git a/Day 12/part1.cpp b/Day 12/part1.cpp
new file mode 100644
index 0000000..143a45b
--- /dev/null
+++ b/Day 12/part1.cpp	
@@ -0,0 +1,72 @@
+#include <iostream>
+#include <cstring>
+#include <string>
+#include <unordered_map>
+#include <set>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+string start = "start";
+string finish = "end";
+
+string lowercase = "qwertyuiopasdfghjklzxcvbnm";
+
+int find_all_paths(unordered_map<string, set<string>> graph, vector<string> current_path);
+
+int main(int argc, char* argv[])
+{
+    unordered_map<string, set<string>> graph;
+
+    string line;
+    while(getline(cin, line))
+    {
+        string::size_type n = line.find("-",0);
+        string node1 = line.substr(0,n);
+        string node2 = line.substr(n+1);
+
+        if (!graph.contains(node1))
+        {
+            graph.emplace(node1, set<string>());
+        }
+
+        if (!graph.contains(node2))
+        {
+            graph.emplace(node2, set<string>());
+        }
+
+        graph[node1].insert(node2);
+        graph[node2].insert(node1);
+    }
+
+    vector<string> beginning_path;
+    beginning_path.push_back(start);
+
+    cout << find_all_paths(graph, beginning_path) << endl;
+}
+
+int find_all_paths(unordered_map<string, set<string>> graph, vector<string> current_path)
+{
+    int found_paths = 0;
+    set<string> connected_nodes = graph[current_path.back()];
+
+    for (set<string>::iterator it = connected_nodes.begin(); it != connected_nodes.end(); ++it)
+    {
+        string current_node = *it;
+
+        if (current_node.compare(finish) == 0)
+        {
+            ++found_paths;
+        }
+        else if (string::npos == current_node.find_first_of(lowercase) ||
+            current_path.end() == std::find(current_path.begin(), current_path.end(), current_node))
+        {   //Big cave or small cave not in path
+            vector<string> next_path(current_path);
+            next_path.push_back(current_node);
+            found_paths += find_all_paths(graph, next_path);
+        }        
+    }
+
+    return found_paths;
+}
\ No newline at end of file
diff --git a/Day 12/part2.cpp b/Day 12/part2.cpp
new file mode 100644
index 0000000..65bbdfb
--- /dev/null
+++ b/Day 12/part2.cpp	
@@ -0,0 +1,80 @@
+#include <iostream>
+#include <cstring>
+#include <string>
+#include <unordered_map>
+#include <set>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+string start = "start";
+string finish = "end";
+
+string lowercase = "qwertyuiopasdfghjklzxcvbnm";
+
+int find_all_paths(unordered_map<string, set<string>> graph, vector<string> current_path, bool double_small_taken);
+
+int main(int argc, char* argv[])
+{
+    unordered_map<string, set<string>> graph;
+
+    string line;
+    while(getline(cin, line))
+    {
+        string::size_type n = line.find("-",0);
+        string node1 = line.substr(0,n);
+        string node2 = line.substr(n+1);
+
+        if (!graph.contains(node1))
+        {
+            graph.emplace(node1, set<string>());
+        }
+
+        if (!graph.contains(node2))
+        {
+            graph.emplace(node2, set<string>());
+        }
+
+        if (0 != node2.compare(start))
+            graph[node1].insert(node2);
+        if (0 != node1.compare(start))
+            graph[node2].insert(node1);
+    }
+
+    vector<string> beginning_path;
+    beginning_path.push_back(start);
+
+    cout << find_all_paths(graph, beginning_path, false) << endl;
+}
+
+int find_all_paths(unordered_map<string, set<string>> graph, vector<string> current_path, bool double_small_taken)
+{
+    int found_paths = 0;
+    set<string> connected_nodes = graph[current_path.back()];
+
+    for (set<string>::iterator it = connected_nodes.begin(); it != connected_nodes.end(); ++it)
+    {
+        string current_node = *it;
+
+        if (current_node.compare(finish) == 0)
+        {
+            ++found_paths;
+        }
+        else if (string::npos == current_node.find_first_of(lowercase) ||
+            current_path.end() == std::find(current_path.begin(), current_path.end(), current_node))
+        {   //Big cave or small cave not in path
+            vector<string> next_path(current_path);
+            next_path.push_back(current_node);
+            found_paths += find_all_paths(graph, next_path, double_small_taken);
+        } 
+        else if (!double_small_taken) 
+        {   //Small cave and in path, double is not taken though
+            vector<string> next_path(current_path);
+            next_path.push_back(current_node);
+            found_paths += find_all_paths(graph, next_path, true);
+        }     
+    }
+
+    return found_paths;
+}
\ No newline at end of file