​

// input = ["dc-end","HN-start","start-kj","dc-start","dc-HN","LN-dc","HN-end","kj-sa","kj-HN","kj-dc"];

​

// input = ["start-A","start-b","A-c","A-b","b-d","A-end","b-end"];

​

function setup() {

  createCanvas(1, 1);

  solve()

}

​

function draw() {

  background(220);

}

​

function solve() {

  let g = makeGraph(input);

  // print(g);

  findPaths(g);  

}

​

function findPaths(g) {

  let num = 0;

  let stack = [['start', {}, false]];

  let dup = "dup";

  while(stack.length > 0) {

    let curr = stack.pop();

    let node = curr[0];

    let visited = curr[1];

    let twice = curr[2];

    // print(curr);

    if(node == "end") {

      num ++;

      // print("At end", num);

    } else {

      if(isLower(node)) {

        if(node in visited) {

          visited[dup] = node;

        } else {

          visited[node] = node;

        }

      }

      let children = g[node];

      // print(children);

      for(let i = 0; i < children.length; i ++) {

        let c = children[i];

        if(isLower(c) && !twice && c in visited && c != "end" && c != "start") {

          let v = d(visited);

          v[c] = c;

          stack.push([c, v, true]);

        }

        if(!isLower(c) || (isLower(c) && !(c in visited))) {

          if(c != "start") {

            v = d(visited);

            v[c] = c;

            stack.push([c, v, twice]);

          }

        }

      }

    }

  }

  print(num);

  print(millis());

}

​

function d(a) {

  return JSON.parse(JSON.stringify(a));

}

function makeGraph() {

  let g = {};

  for(let i = 0; i < input.length; i ++) {

    let caves = input[i].split("-");

    let c1 = caves[0];

    let c2 = caves[1];

    if(!(c1 in g)) {

      g[c1] = [];

    }

    g[c1].push(c2);

    if(!(c2 in g)) {

      g[c2] = [];

    }

    g[c2].push(c1);

  }

  return g;

}

​

function isLower(s) {

  return s.toLowerCase() == s;

}