In an array A of 0s and 1s, how many non-empty subarrays have sum S?
 
Example 1:
Input: A = [1,0,1,0,1], S = 2
Output: 4
Explanation: 
The 4 subarrays are bolded below:
[1,0,1,0,1]
[1,0,1,0,1]
[1,0,1,0,1]
[1,0,1,0,1]

 
Note:

A.length <= 30000
0 <= S <= A.length
A[i] is either 0 or 1.

```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 numSubarraysWithSum(self, A: List[int], S: int) -> int:\n        def findZerosBefore(index, array):\n            zerosBefore = 0\n            index -= 1\n            while (index >= 0 and array[index] != 1):\n                zerosBefore += 1\n                index -= 1\n            return zerosBefore\n    \n        def findZerosAfter(index, array):\n            zerosAfter = 0\n            index += 1\n            while (index < len(array) and array[index] != 1):\n                zerosAfter += 1\n                index += 1\n            return zerosAfter\n        def zeroString(index, array):\n            zeros = 0\n            while (index < len(array) and array[index] != 1):\n                zeros += 1\n                index += 1\n            \n            return zeros\n            \n        def zeroCombs(n):\n            combs = 0\n            for i in range(n, 0, -1):\n                combs = combs + n - i + 1\n            return combs\n            \n        def firstZero(index, array):\n            if (index == 0):\n                return True\n            if (array[index - 1] == 1):\n                return True\n            else:\n                return False\n                    \n        total = 0\n        \n        if (S > 0):\n            # get indices of all ocurrences of 1 in 'A'\n            one_array = [i for i, one in enumerate(A) if one == 1]\n            print(one_array)\n            start_index = []\n            end_index = []\n\n            for n in range(len(one_array)):\n                if (n + S - 1 < len(one_array)):\n                    start_index.append(one_array[n])\n                    end_index.append(one_array[n + (S - 1)])\n            print(start_index)\n            print(end_index)\n            for i in range(len(start_index)):\n                Bef = findZerosBefore(start_index[i], A)\n                print(Bef)\n                Aft = findZerosAfter(end_index[i], A)\n                total = total + Bef + Aft + (Bef * Aft) + 1\n        \n        if (S == 0):\n            zero_array = [i for i, zero in enumerate(A) if zero == 0]\n            for n in range(len(zero_array)):\n                if (firstZero(zero_array[n], A)):\n                    sticky = zeroString(zero_array[n], A)\n                    total = total + zeroCombs(sticky)\n        \n        return total\n                \n                \n                \n            \n            \n            \n    \n            \n            \n            \n            \n            \n        \n        \n                \n                \n    \n"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'numSubarraysWithSum'
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: 8016