1658

class Solution {
public:
    int minOperations(vector<int>& nums, int x) {
        int sum = accumulate(nums.begin(), nums.end(), 0)-x;
        int  left, right, len=-1, csum=0;

        for(left=0, right=0; right<nums.size(); right++){
            csum += nums[right];
            while(left < nums.size() && csum > sum)
                csum -= nums[left++];
            if(csum == sum)
                    len = max(len, right-left+1);
        }
        return (len == -1) ? -1 : nums.size()-len;
    }
};