删除元素

public class Solution {
    /** 
     *@param A: A list of integers
     *@param elem: An integer
     *@return: The new length after remove
     */
    public int removeElement(int[] A, int elem) {
        int i = 0;
        int j = A.length - 1;
        while (i <= j) {
            if (A[i] == elem) {
                A[i] = A[j];
                j--;
            } else {
                i++;
            }
        }
        return i;
    }
}