给定数组和一个值，去掉该数组中的这个值，返回新数组长度。
要求操作是in place的，返回的数组元素位置可变，新数组之后的部分无所谓。
Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn‘t matter what you leave beyond the new length.
与remove duplicates from sorted array相似.
public class Solution { public int removeElement( int[] A, int elem ){ int len = 0; for( int i=0; i<A.length; i++ ) if( A[i]!=elem && i!=len++) A[len-1] =A[i]; return len; } }
原文：http://www.cnblogs.com/hf-cherish/p/4598690.html
