977. Squares of a Sorted Array有序数组的平方

class Solution {
public:
    vector<int> sortedSquares(vector<int>& A) {
        int i = 0, j = A.size()-1;
        vector<int> ans;
        while(i != j)
        {
            if(abs(A[i]) < abs(A[j]))
            {
                ans.push_back(A[j]*A[j]);
                j--;
            }
            else
            {
                ans.push_back(A[i]*A[i]);
                i++;
            }
        }
        ans.push_back(A[i]*A[i]);
        reverse(ans.begin(), ans.end());
        return ans;
    }
};