Leetcode-954 Array of Doubled Pairs(二倍数对数组)

class Solution
{
    public:
        bool canReorderDoubled(vector<int>& A)
        {
            if(A.empty())
                return true;
            sort(A.begin(),A.end());
            int zcnt = 0;
            int sz = A.size();
            for(int i = 0; i < sz; i ++)
            {
                if(A[i]>0)
                {
                    int pos1 = lower_bound(A.begin(),A.end(),A[i]*2)-A.begin();
                    if(pos1==A.size()||A[pos1]!=2*A[i])
                        return false;
                    A.erase(A.begin()+pos1);
                    sz --;
                }
                else if(A[i]<0)
                {
                    int pos2 = lower_bound(A.begin(),A.end(),A[i]/2)-A.begin();
                    if(pos2==A.size()||A[pos2]!=A[i]/2)
                        return false;
                    A.erase(A.begin()+pos2);
                    sz --;
                }
                else if(A[i]==0)
                    zcnt ++;
            }
            return (zcnt%2)==0;
        }
};

真-瞎j8写写就过了