leetCode 26.Remove Duplicates from Sorted Array(删除数组反复点) 解题思路和方法

Remove Duplicates from Sorted Array

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.

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

For example,

Given input array nums = [1,1,2],

Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively. It doesn’t matter what you leave beyond the new length.

思路：此题比較简单。大意是将数组中反复点删除，然后返回新数组的长度。数组中前n个数就是新的数组。唯一难点是不能用额外空间。

具体代码例如以下：

public class Solution {
    public int removeDuplicates(int[] nums) {
        if(nums.length <= 1){
            return nums.length;
        }
        int len = 1;//新的长度，至少为1,下面循环从i=1開始
        for(int i = 1; i < nums.length; i++){
            if(nums[i] != nums[i-1]){//不等于前一个元素。长度+1
                nums[len++] = nums[i];//将新的元素装到前len个
            }
        }
        return len;
    }
}