Shortest Path Visiting All Nodes

export function shortestPathLength(graph: number[][]): number {
  const n = graph.length;
  if (n <= 3) {
    return n - 1;
  }
 
  const visited: number[] = new Array(n).fill(undefined).map((_, i) => 1 << i);
  const allVisited = (1 << n) - 1;
  const visitedState: Set<number>[] = new Array(n)
    .fill(undefined)
    .map((_, i) => new Set([visited[i]]));
 
  let queue: [number, number][] = new Array(n).fill(undefined).map((_, i) => [i, visited[i]]);
  let currentStep = 0;
  while (0 < queue.length) {
    const nextQueue: [number, number][] = [];
    for (const [currentNode, currentVisited] of queue) {
      for (const nextNode of graph[currentNode]) {
        const nextVisited = currentVisited | visited[nextNode];
        if (nextVisited === allVisited) {
          return currentStep + 1;
        }
        if (!visitedState[nextNode].has(nextVisited)) {
          visitedState[nextNode].add(nextVisited);
          nextQueue.push([nextNode, nextVisited]);
        }
      }
    }
    queue = nextQueue;
    currentStep += 1;
  }
 
  throw new Error('모든 노드를 방문할 수 없습니다.');
}