<p>Given an array of integers <code>nums</code> and an integer <code>k</code>. A continuous subarray is called <strong>nice</strong> if there are <code>k</code> odd numbers on it.</p>

<p>Return <em>the number of <strong>nice</strong> sub-arrays</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,1,2,1,1], k = 3
<strong>Output:</strong> 2
<strong>Explanation:</strong> The only sub-arrays with 3 odd numbers are [1,1,2,1] and [1,2,1,1].
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,4,6], k = 1
<strong>Output:</strong> 0
<strong>Explanation:</strong> There are no odd numbers in the array.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,2,2,1,2,2,1,2,2,2], k = 2
<strong>Output:</strong> 16
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 50000</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10^5</code></li>
	<li><code>1 &lt;= k &lt;= nums.length</code></li>
</ul>

static const bool Booster = [](){
    std::ios_base::sync_with_stdio(false);
    std::cout.tie(nullptr);
    std::cin.tie(nullptr);
    return true;
}();

constexpr size_t MAX_LEN = 100'000;
static std::array<int, MAX_LEN> mp;

inline bool is_odd(int n) {
    return (n % 2) == 1;
}
inline bool is_even(int n) {
    return !is_odd(n);
}

int parse_input_and_solve(const std::string& s, const int k) {
    const size_t M = s.size();
    const size_t N = std::min(M - 2, MAX_LEN);
    std::fill(std::begin(mp), std::begin(mp) + N, 0);
    mp[0] = 1;
    int prefixSum = 0;
    int subNum = 0;
    int number = 0;
    for (int i = 1; i < M; ++i) {
        if (s[i] == ']' || s[i] == ',') {
            if (is_odd(number)) {
                prefixSum++;
            }
            mp[prefixSum]++;
            if (prefixSum - k >= 0) {
                subNum += mp[prefixSum - k];
            }
            number = 0;
            continue;
        }
        number = 10 * number + (s[i] - '0');
    }
    return subNum;
}

static bool Solve = [](){
    std::ofstream out("user.out");
    std::string nums_, k_;
    while (std::getline(std::cin, nums_) && std::getline(std::cin, k_)) {
        const int k = std::stoi(k_);
        out << parse_input_and_solve(nums_, k) << "\n";
    }
    out.flush();
    exit(0);
    return true;
}();

class Solution {
public:
    int numberOfSubarrays(std::vector<int>& nums, int k) {
        const int N = nums.size();
        int subNum = 0;
        std::fill(std::begin(mp), std::begin(mp) + N, 0);
        mp[0] = 1;
        int prefixSum = 0;
        for (int i = 0; i < N; ++i) {
            if (is_odd(nums[i])) {
                prefixSum++;
            }
            mp[prefixSum]++;
            if (prefixSum - k >= 0) {
                subNum += mp[prefixSum - k];
            }
        }
        return subNum;
    }
};
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