---
id: bfs
title: "Breadth First Search"
author: Benjamin Qi
prerequisites: 
 - Silver - Depth First Search
description: "Traversing a graph in a way such that vertices closer to the starting vertex are processed first."
frequency: 2
---

import { Problem } from "../models";

export const metadata = {
  problems: {
    sample: [
      new Problem("CSES", "Message Route", "1667", "Easy", false, ["BFS"]),
    ],
    general: [
      new Problem("CSES", "Monsters", "1194", "Easy", false, ["BFS"]),
      new Problem("Gold", "Cow Navigation", "695", "Easy", false, ["BFS"], "lots of casework"),
      new Problem("CSA", "BFS-DFS", "bfs-dfs", "Normal", false, ["BFS", "DFS"]),
      new Problem("Gold", "Lasers", "671", "Normal", false, ["BFS"]),
      new Problem("Gold", "Dream", "575", "Hard", false, ["BFS"]),
    ],
  }
};

<info-block title="Pro Tip">
No silver problem should require BFS rather than DFS, but it's still good to know at this level.
</info-block>

## Sample

<problems-list problems={metadata.problems.sample} />

## Tutorial

 - CPH 12.2
 - [PAPS 12.1](https://www.csc.kth.se/~jsannemo/slask/main.pdf)
 - [CSAcademy BFS](https://csacademy.com/lesson/breadth_first_search)
 - [cp-algo BFS](https://cp-algorithms.com/graph/breadth-first-search.html)
 - [cp-algo 0/1 BFS](https://cp-algorithms.com/graph/01_bfs.html)
 - [KhanAcademy BFS](https://www.khanacademy.org/computing/computer-science/algorithms/breadth-first-search/a/breadth-first-search-and-its-uses)

## Problems

<problems-list problems={metadata.problems.general} />