1248

class Solution {
public:
    int numberOfSubarrays(vector<int>& nums, int k) {
        int ans, left, right, count;
        ans = left = right = count = 0;
        int sz = nums.size();
        int fans = 0;
       for(right=0; right<sz; right++){
           if(nums[right] & 1) count++, ans=0;
           while(count == k){
               ans++;
               if(nums[left++] & 1) count--;
           }
           fans += ans;
       }
       return fans;
    }
};