[Leetcode]Leetcode 27:Remove Element

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.

解题思路：

两个要求：一是计数移除元素之后的新数组的长度，二是让新数组的前几位为移除之后的所有元素。注意：不要使用新的空间

所以在这个题里可以尝试两个指针，一个用来比较数组每一个元素（遍历控制阵阵位置，一个用来移动数组剩余元素（通过新数组长度来控制指针位置）

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

return len;
}
}