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输入：nums = [1,2,3,1], k= 3
输出：true

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输入：nums = [1,0,1,1], k=1
输出：true

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输入：nums = [1,2,3,1,2,3], k=2
输出：false

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// @lc code=start
impl Solution {
    /// ## 解题思路
    /// - hashset + 滑动窗口
    /// 1. 设置set滑窗;
    /// 2. 从左至右遍历nums[i];
    /// 3. 如果i > k, 则缩小set 窗口最左边的元素;
    /// 4. 如果nums[i]在滑窗中, 则返回true;
    /// 5. 否则将nums[i]加入到滑窗中;
    /// 6. 遍历玩后, 没有触发4, 则返回false;
    pub fn contains_nearby_duplicate(nums: Vec<i32>, k: i32) -> bool {
        if nums.len() == 0 || k == 0 {
            return false;
        }
        let k = k as usize;
        use std::collections::HashSet;
        let mut tmp_win: HashSet<i32> = HashSet::with_capacity(k);
        for (i, &n) in nums.iter().enumerate() {
            if i > k {
                tmp_win.remove(&nums[i - k - 1]);
            }
            if tmp_win.contains(&n) {
                return true;
            }
            tmp_win.insert(n);
        }

        return false;
    }
}
// @lc code=end

struct Solution;