Get Watched Videos by Your Friends LeetCode solution in Rust

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use std::collections::{HashMap, VecDeque};
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impl Solution {
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  pub fn watched_videos_by_friends(
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    watched_videos: Vec<Vec<String>>,
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    friends: Vec<Vec<i32>>,
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    id: i32,
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    level: i32,
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  ) -> Vec<String> {
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    let mut queue = VecDeque::from([id as usize]);
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    let mut visited = vec![false; friends.len()];
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    visited[id as usize] = true;
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    for _ in 0..level {
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      let len = queue.len();
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      for _ in 0..len {
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        if let Some(node) = queue.pop_front() {
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          for nei in friends[node as usize].iter().map(|&nei| nei as usize) {
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            if !visited[nei] {
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              queue.push_back(nei);
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              visited[nei] = true;
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            }
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          }
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        }
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      }
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    }
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    let mut watched_videos = queue
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      .into_iter()
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      .fold(HashMap::new(), |mut freq, user| {
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        watched_videos[user].iter().fold(freq, |mut freq, v| {
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          *freq.entry(v).or_insert(0) += 1;
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          freq
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        })
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      })
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      .into_iter()
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      .collect::<Vec<_>>();
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    watched_videos.sort_unstable_by(|(v_a, f_a), (v_b, f_b)| {
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      if f_a == f_b {
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        v_a.cmp(&v_b)
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      } else {
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        f_a.cmp(&f_b)
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      }
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    });
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    watched_videos
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      .into_iter()
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      .map(|(v, _)| v.to_string())
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      .collect()
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  }
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}