AoC 2021 day 12

#include <Arduino.h>

char testData[][2][6]= {
{"dc","end"},
{"HN","start"},
{"start","kj"},
{"dc","start"},
{"dc","HN"},
{"LN","dc"},
{"HN","end"},
{"kj","sa"},
{"kj","HN"},
{"kj","dc"}};

char data[][2][6]= {
{"end","MY"},
{"MY","xc"},
{"ho","NF"},
{"start","ho"},
{"NF","xc"},
{"NF","yf"},
{"end","yf"},
{"xc","TP"},
{"MY","qo"},
{"yf","TP"},
{"dc","NF"},
{"dc","xc"},
{"start","dc"},
{"yf","MY"},
{"MY","ho"},
{"EM","uh"},
{"xc","yf"},
{"ho","dc"},
{"uh","NF"},
{"yf","ho"},
{"end","uh"},
{"start","NF"}
};

typedef struct Node {
  int id;
  int visited = 0;
  bool bigRoom = false;
  int nodes[10];
  int index = 0;
};

typedef struct  Graph{
  Node nodes[20];
  char nodeDict[20][6];
  int index = 0;
};
Graph graph;

int getNode(char* a){
  for(int i = 0; i < graph.index; i++){
    if(strcmp(graph.nodeDict[i], a) == 0){
      return i;
    }
  }
}

void addToGraph(char* a){
  for(int i = 0; i < graph.index; i++){
    if(strcmp(graph.nodeDict[i], a) == 0){
      return;
    }
  }
  graph.nodes[graph.index].id = graph.index;
  if(isUpperCase(a[0]))graph.nodes[graph.index].bigRoom = true;
  strcpy(graph.nodeDict[graph.index], a);
  graph.index++;
}

void addToNode(Node &na, Node &nb){
  na.nodes[na.index]=nb.id;
  na.index++;
  nb.nodes[nb.index]=na.id;
  nb.index++;
}

void addConnection(char* a, char* b){
  addToGraph(a);
  addToGraph(b);
  addToNode(graph.nodes[getNode(a)],graph.nodes[getNode(b)]);
}

void searchpath(Node &node, long& count, bool visitedTwice)
{
    node.visited++;
    if (node.id == 1)
    {
        count++;
        node.visited = 0;
        return;
    }

    for (int index = 0; index < node.index; index++)
    {
        Node n = graph.nodes[node.nodes[index]];

    if (n.id == 0)
            continue;

        bool visited = visitedTwice;
        if (n.visited > 0 && n.bigRoom == false && visitedTwice)
            continue;
        else if (n.visited > 0 && n.bigRoom == false )
            visited = true;

        searchpath(graph.nodes[node.nodes[index]], count,visited);
    }

    node.visited--;
}

void setup() {

  Serial.begin(9600);
  while(!Serial);

  addToGraph("start");
  addToGraph("end");
  for (int i=0; i<sizeof data/sizeof data[0]; i++) {
    char* s = data[i][0];
    char* e = data[i][1];
    addConnection(s,e);
  }

  long count = 0;
  long time = millis();

  searchpath(graph.nodes[0], count, true);
  Serial.print("Nummber of routes part 1: ");
  Serial.println(count);
  Serial.print("Millisec: ");
  Serial.println(millis() - time);

  for(int i = 0; i < graph.index; i++){
    graph.nodes[i].visited = 0;
  }

  count = 0;
  time = millis();

  searchpath(graph.nodes[0], count, false);
  Serial.print("Nummber of routes part 2: ");
  Serial.println(count);
  Serial.print("Millisec: ");
  Serial.println(millis() - time);
}

void loop() {
  // put your main code here, to run repeatedly:
}