Given an array of integers A, find the sum of min(B), where B ranges over every (contiguous) subarray of A.
Since the answer may be large, return the answer modulo 10^9 + 7.
 
Example 1:
Input: [3,1,2,4]
Output: 17
Explanation: Subarrays are [3], [1], [2], [4], [3,1], [1,2], [2,4], [3,1,2], [1,2,4], [3,1,2,4]. 
Minimums are 3, 1, 2, 4, 1, 1, 2, 1, 1, 1.  Sum is 17.
 
Note:

1 <= A.length <= 30000
1 <= A[i] <= 30000

```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 sumSubarrayMins(self, A: List[int]) -> int:\n        \n        stack = []\n        mult = 0\n        ans = 0\n        \n        for curr_val in A:\n            curr_cnt = 1\n            while stack and stack[-1][0] >= curr_val:\n                val_p, cnt_p = stack.pop()\n                curr_cnt += cnt_p\n                mult -= val_p * cnt_p\n            stack.append((curr_val, curr_cnt))\n            mult += curr_val * curr_cnt\n            ans += mult\n        return ans % (10**9 + 7)\n        \n        \n        \n        \n        ## Two-Pass\n#         CNT = 0\n#         VAL = 1\n#         N = len(A)\n#         left = [0] * N\n#         right = [0] * N\n        \n#         def sum_of_single_min(idx):\n#             return A[idx] * left[idx] * right[idx]\n        \n#         stack = []\n#         for i, curr_val in enumerate(A):\n#             curr_cnt = 1\n#             while stack and stack[-1][VAL] > curr_val:\n#                 curr_cnt += stack.pop()[CNT]\n#             stack.append((curr_cnt, curr_val))\n#             left[i] = curr_cnt\n        \n#         stack = []\n#         for i in range(N-1, -1, -1):\n#             curr_val = A[i]\n#             curr_cnt = 1\n#             while stack and stack[-1][VAL] >= curr_val:\n#                 curr_cnt += stack.pop()[CNT]\n#             stack.append((curr_cnt, curr_val))\n#             right[i] = curr_cnt\n        \n#         return sum(sum_of_single_min(i) for i in range(N)) % (10**9 + 7)\n        \n        \n        \n        \n'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'sumSubarrayMins'
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: 5634