class Solution {
public:
    int movesToMakeZigzag(vector<int>& nums) {
        if (nums.size() <= 1) return 0;
        int len = nums.size();
        int ret1 = 0, ret2 = 0;
        for (int i = 0; i < len; i += 2) {
            int t;
            if (i-1 < 0) t = nums[i+1];
            else if (i+1 >= len) t = nums[i-1];
            else t = min(nums[i+1], nums[i-1]);
            if (nums[i] >= t)
                ret1 += nums[i] - t + 1;
        }
        for (int i = 1; i < len; i += 2) {
            int t;
            if (i-1 < 0) t = nums[i+1];
            else if (i+1 >= len) t = nums[i-1];
            else t = min(nums[i+1], nums[i-1]);
            if (nums[i] >= t)
                ret2 += nums[i] - t + 1;
        }
        return min(ret1, ret2);
    }
};