searchGraph.ts

const graph = {
  1: [2, 3, 4],
  2: [1, 5],
  3: [1, 5],
  4: [1, 6],
  5: [2, 3, 7],
  6: [4, 7],
  7: [5, 6],
};

function searchGraph(start: number) {
  let result: number[] = [start];
  const map: Map<number, number> = new Map();
  map.set(start, start);
  let needToGetNeighbors = graph[start] as number[];
  let i = 0;
  while (i < needToGetNeighbors.length) {
    const neighbor = needToGetNeighbors[i];
    if (map.get(neighbor) === undefined) {
      result.push(neighbor);
      map.set(neighbor, neighbor);
    }
    const newNeighbors = graph[neighbor] as number[];
    const newNeedToGetNeighbors = newNeighbors.filter(
      (newNeighbor) => map.get(newNeighbor) === undefined
    );
    needToGetNeighbors = needToGetNeighbors.concat(newNeedToGetNeighbors);
    i += 1;
  }
  return result;
}