# 219. Contains Duplicate II

#### Easy

***

Given an integer array `nums` and an integer `k`, return `true` if there are two **distinct indices** `i` and `j` in the array such that `nums[i] == nums[j]` and `abs(i - j) <= k`.

&#x20;

**Example 1:**

<pre><code>Input: nums = [1,2,3,1], k = 3
<strong>Output:
</strong> true
</code></pre>

**Example 2:**

<pre><code>Input: nums = [1,0,1,1], k = 1
<strong>Output:
</strong> true
</code></pre>

**Example 3:**

<pre><code>Input: nums = [1,2,3,1,2,3], k = 2
<strong>Output:
</strong> false
</code></pre>

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**Constraints:**

* `1 <= nums.length <= 105`
* `-109 <= nums[i] <= 109`
* `0 <= k <= 105`

```python
class Solution:
    def containsNearbyDuplicate(self, nums: List[int], k: int) -> bool:
        d = defaultdict(list)
        for index,val in enumerate(nums):
            d[val].append(index)
        for key, l in d.items():
            if len(l) == 1:
                continue
            for i in range(1, len(l)):
                if abs(l[i] - l[i-1]) <= k:
                    return True
        return False
```