leetcode

0 class Solution {

1 public:

2 int minKBitFlips(vector<int> &nums, int k) const {

3 const int n = size(nums);

4 int res = 0, flips = 0;

5

6 for (int i = 0; i < n; i++) {

7 if (nums[i] == flips % 2) {

8 if (i > n - k) return -1;

9 nums[i] -= 2, res++, flips++;

10 }

11

12 const int prev = i - k + 1;

13 if (i >= k - 1 && nums[prev] < 0) nums[prev] += 2, flips--;

14 }

15

16 return res;

17 }

18 };