<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>

static const bool Booster = [](){
    std::ios_base::sync_with_stdio(false);
    std::cout.tie(nullptr);
    std::cin.tie(nullptr);
    return true;
}();


class Solution {
public:
    int noOfSubArr(vector<int>arr,int target){
        if(target<0)return 0;

        int sum=0;
        int i=0,j=0;
        int total=0;

        while(j<arr.size())
        {
            sum+=arr[j];

            while(sum>target)sum-=arr[i++];

            if(sum<=target)total+=(j-i+1);

            j++;
        }

        return total;
    }



    int numberOfSubarrays(vector<int>& nums, int k) {
        for(int i=0; i<nums.size(); i++)
        {
            if(nums[i]%2==1)nums[i]=1;
            else nums[i]=0;
            cout<<nums[i]<<" ";
        }
        cout<<endl;

        cout<<noOfSubArr(nums,k)<<" "<<noOfSubArr(nums,k-1)<<endl;

        return noOfSubArr(nums,k)-noOfSubArr(nums,k-1);
    }
};
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