Leet Code Daily 2024-06-24 - Minimum Number of K Consecutive Bit Flips

class Solution {
public:
    int minKBitFlips(vector<int>& nums, int k) {
        int n = nums.size(), ans = 0;
        queue<int> flip_upper_bounds;
        for (int i = 0; i < n; i++) {
            while (!flip_upper_bounds.empty() &&
                   flip_upper_bounds.front() < i) {
                flip_upper_bounds.pop();
            }
            if ((nums[i] + flip_upper_bounds.size()) % 2 == 0) {
                if (i + k - 1 < n) {
                    flip_upper_bounds.push(i + k - 1), ans++;
                } else {
                    return -1;
                }
            }
        }
        return ans;
    }
};