# 992. Subarrays with K Different Integers

## Problem Statement

<br>

Given an integer array `nums` and an integer `k`, return *the number of **good subarrays** of* `nums`.

A **good array** is an array where the number of different integers in that array is exactly `k`.

* For example, `[1,2,3,1,2]` has `3` different integers: `1`, `2`, and `3`.

A **subarray** is a **contiguous** part of an array.

&#x20;

**Example 1:**

<pre><code><strong>Input: nums = [1,2,1,2,3], k = 2
</strong><strong>Output: 7
</strong><strong>Explanation: Subarrays formed with exactly 2 different integers: [1,2], [2,1], [1,2], [2,3], [1,2,1], [2,1,2], [1,2,1,2]
</strong></code></pre>

**Example 2:**

<pre><code><strong>Input: nums = [1,2,1,3,4], k = 3
</strong><strong>Output: 3
</strong><strong>Explanation: Subarrays formed with exactly 3 different integers: [1,2,1,3], [2,1,3], [1,3,4].
</strong></code></pre>

&#x20;

**Constraints:**

* `1 <= nums.length <= 2 * 104`
* `1 <= nums[i], k <= nums.length`

## Intuition

```
Approach :
Use atmost approach to get exactly k elements

Basically at every point in high-low+1

We add extra subarrays

example 
1 2 1 2 3
l h

h-l+1
adds 2 here which is, 2, 1 2
Count 
```

### Links

<https://leetcode.com/problems/subarrays-with-k-different-integers/description/>

### Video Links

### Approach 1:

```
Atmost Sliding Window
```

{% code title="C++" lineNumbers="true" %}

```cpp
class Solution {
public:
    int Atmost(vector<int>& nums, int k){
        unordered_map<int, int> mp;
        int low=0;
        int ans=0;

        for(int high=0; high<nums.size(); high++){
            mp[nums[high]]++;

            while(mp.size() > k){
                if(mp[nums[low]] == 1)
                    mp.erase(nums[low]);
                else
                    mp[nums[low]]--;

                low++;
            }

            ans += high-low+1;
        } 

        return ans;
    }

    int subarraysWithKDistinct(vector<int>& nums, int k) {
        return Atmost(nums, k) - Atmost(nums, k-1);
    }
};
```

{% endcode %}

### Approach 2:

```
```

{% code title="C++" lineNumbers="true" %}

```cpp
```

{% endcode %}

### Approach 3:

```
```

{% code title="C++" lineNumbers="true" %}

```cpp
```

{% endcode %}

### Approach 4:

```
```

{% code title="C++" lineNumbers="true" %}

```cpp
```

{% endcode %}

### Similar Problems

<https://leetcode.com/problems/binary-subarrays-with-sum/description/>\
<https://leetcode.com/problems/count-number-of-nice-subarrays/description/>\ <br>

###


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://coding-9.gitbook.io/untitled/sliding-window/medium/992.-subarrays-with-k-different-integers.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.