<p>Given an array of integers <code>nums</code> and an integer <code>k</code>. A continuous subarray is called <strong>nice</strong> if there are <code>k</code> odd numbers on it.</p>

<p>Return <em>the number of <strong>nice</strong> sub-arrays</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,1,2,1,1], k = 3
<strong>Output:</strong> 2
<strong>Explanation:</strong> The only sub-arrays with 3 odd numbers are [1,1,2,1] and [1,2,1,1].
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,4,6], k = 1
<strong>Output:</strong> 0
<strong>Explanation:</strong> There are no odd numbers in the array.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,2,2,1,2,2,1,2,2,2], k = 2
<strong>Output:</strong> 16
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 50000</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10^5</code></li>
	<li><code>1 &lt;= k &lt;= nums.length</code></li>
</ul>

class Solution {
public:
    int numberOfSubarrays(vector<int>& nums, int k) {
        int i=0;
        int j=0;

       unordered_map<int,int>mp;

       for(int i=0; i<nums.size(); i++)
       {
            if(nums[i]%2!=0)
            mp[nums[i]]++;
       }

       int cnt=0;
       int nice=0;

       while(j<nums.size())
        {
            if(nums[j]%2!=0)
            {
                cnt++;
               mp[nums[j]]--;
                
            }

            while(cnt>k)
            {
                if(nums[i]%2!=0)
                {
                    cnt--;
                   mp[nums[i]]++;
                }
                i++;
                
            }
            if(cnt==k)
            {
                nice++;
              
                int tempi=i;
                while(tempi<j && nums[tempi]%2==0)
                {
                    nice++;
                    tempi++;
                }
            }

            j++;
            
            
        }
       return nice;
    
    }
};
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