https://leetcode.com/problems/count-number-of-nice-subarrays

class Solution {
public:
    int numberOfSubarrays(vector<int>& nums, int k) {
        int n=nums.size();
        vector<int> pos;
        int res=0;
        int count=0;
        for(int i=0;i<n;i++)
        {
            if(nums[i]%2!=0)
            {
                pos.push_back(i);
            }
        }
        // for(auto x:pos)
        // {
        //     cout<<x<<", ";
        // }cout<<endl;
        int i=0;
        int j=k-1;
        int left=0;
        int right=0;
        int m=pos.size();
        while(i<m && j<m)
        {


           // cout<<pos[i]<<" "<<pos[j]<<endl;
            if(i==0 && pos[i]==0)
                left=1;
            else if( i==0 && pos[i]!=0)
                left= pos[i]+1;
            else
                left=pos[i]-pos[i-1];

            if(j==m-1 && pos[j]==n-1)
                right=1;
            else if(j==m-1 && pos[j]!=n-1)
                right=(n-1)-pos[j]+1;
            else
                right=pos[j+1]-pos[j];

            res+=(left*right);
            i++;
            j++;
        }


       // cout<<"--"<<endl;
        return res;
    }
};