Leetcode-26-easy Remove Duplicates from Sorted array

Leetcode-26-easy Remove Duplicates from Sorted array

Question

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.

Solution

解决的方法很简单，只要用双指针的想法记录下尾部序号即可

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

用时14ms