27. Remove Element

问题描述：

Given an array and a value, remove all instances of that value in place and return the new length.

Do not allocate extra space for another array, you must do this in place with constant memory.

The order of elements can be changed. It doesn't matter what you leave beyond the new length.

Example:
Given input array nums = [3,2,2,3], val = 3

Your function should return length = 2, with the first two elements of nums being 2.

这个问题很简单，只要每次循环判断是否是目标数字。如果是就count++，如果不是就把这个数放到最前面，其他count个目标数放到后面。

我的解法：

class Solution {    public int removeElement(int[] nums, int val) {        int len= nums.length;        int count = 0;        for(int i=0;i<nums.length;i++){            if(nums[i]==val)                             count++;            if(nums[i]!=val){                nums[i-count] = nums[i];                for(int j = 0;j<count;j++){                    nums[i-j]=val;                }            }        }        return len-count;    }}

大神的解法：

int removeElement(int A[], int n, int elem) {    int begin=0;    for(int i=0;i<n;i++) if(A[i]!=elem) A[begin++]=A[i];    return begin;}