Remove Duplicates from Sorted Array

Posted 2020-07-06 no_one

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 A = [1,1,2],
Your function should return length = 2, and A is now [1,2].

分析：在排好序的数组中去除重复。从左到右遍历比较即可。

时间复杂度O(n)，空间复杂度O(1)

public class Solution {
    public int removeDuplicates(int[] nums) {
        if(nums.length == 0) return 0;
        int index = 0;
        for(int i=1; i<nums.length; i++) {
            if(nums[index] != nums[i]) {
                nums[++index] = nums[i]; 
            }
        }
        return index + 1;
    }
}