Given an array of integers nums and an integer k. A continuous subarray is called nice if there are k odd numbers on it.
Return the number of nice sub-arrays.
 
Example 1:
Input: nums = [1,1,2,1,1], k = 3
Output: 2
Explanation: The only sub-arrays with 3 odd numbers are [1,1,2,1] and [1,2,1,1].

Example 2:
Input: nums = [2,4,6], k = 1
Output: 0
Explanation: There is no odd numbers in the array.

Example 3:
Input: nums = [2,2,2,1,2,2,1,2,2,2], k = 2
Output: 16

 
Constraints:

1 <= nums.length <= 50000
1 <= nums[i] <= 10^5
1 <= k <= nums.length

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

def _disabled_input(*args, **kwargs):
    raise RuntimeError("input() is disabled in callable mode")
builtins.input = _disabled_input

ns = {"__name__": "__judge__"}  # prevent if __name__ == "__main__" blocks
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = "class Solution:\n    def numberOfSubarrays(self, nums: List[int], k: int) -> int:\n        '''\n        This is not an atmost/atleast constraint. \n        Soln pattern is different for atleast constraint\n        refer this https://leetcode.com/problems/number-of-substrings-containing-all-three-characters/\n        This is an exact constraint, so different thinking is required\n        \n        Nice solution is explained here\n        https://leetcode.com/problems/count-number-of-nice-subarrays/discuss/419378/JavaC%2B%2BPython-Sliding-Window-O(1)-Space\n        Two methods are given.\n        1) uses standard templete to find subarray with atmost k odd numbers\n        2) modifies this template slightly to accomodate exactly k odd numbers constraint\n        '''\n        # return self.sol2(nums, k)\n        return self.sol1(nums, k) - self.sol1(nums, k-1)\n    \n    def sol1(self, nums, k):\n        '''\n        Exactly k ones = atMost(k ones) - atMost(k-1 ones)\n        '''\n        start = 0\n        odds = 0\n        res = 0\n        for end in range(len(nums)):\n            odds += nums[end] & 1\n            while odds > k:\n                '''Inc start till constraint is violated'''\n                odds -= nums[start] & 1\n                start += 1\n            \n            '''\n            This will add all sub arrays from size 1,2..end-start for every iteration\n            Since we are doing atMost(k) even if sub array does not contain any odd number we still have to add it to res even if its size is 1\n            '''\n            res += end - start + 1\n            # print(res)    \n        return res\n    \n    def sol2(self, nums, k):\n        start = 0\n        odds = 0\n        res = 0\n        count = 0\n        for end in range(len(nums)):\n            if nums[end] & 1: # nums[end] is odd\n                odds += 1\n                count = 0 # reset counter to avoid repeated addition to result\n                \n            while odds >= k:\n                if nums[start] & 1:\n                    odds -= 1\n                    \n                start += 1\n                count += 1\n                # print(end, start)\n                \n                \n            res += count\n                \n        return res\n"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'numberOfSubarrays'
if _fn_name:
    if "Solution" in ns:
        try:
            _obj = ns["Solution"]()
            if hasattr(_obj, _fn_name):
                _target = getattr(_obj, _fn_name)
        except Exception:
            _target = None
    if _target is None and _fn_name in ns and callable(ns[_fn_name]):
        _target = ns[_fn_name]
# Fallback: if there's exactly one user-defined function, use it
if _target is None:
    _cands = [v for k, v in ns.items() if callable(v) and getattr(v, "__module__", "") in ("__judge__", "__main__")]
    _user_funcs = [c for c in _cands if getattr(c, "__name__", "").startswith("_") is False]
    if len(_user_funcs) == 1:
        _target = _user_funcs[0]
if _target is None:
    raise RuntimeError(f"Could not resolve callable '{_fn_name}'")

_raw = sys.stdin.read().strip()
if _raw:
    _parsed = json.loads(_raw)
    if isinstance(_parsed, dict):
        _kwargs = _parsed.get("kwargs", {})
        _args = _parsed.get("args", [])
    else:
        _args, _kwargs = _parsed, {}
else:
    _args, _kwargs = [], {}
if not isinstance(_args, (list, tuple)):
    _args = [_args]
_res = _target(*_args, **_kwargs)
try:
    sys.stdout.write(repr(_res) + "\n")
except Exception:
    pass

```

Measured memory_bytes: 5554