LeetCode每日一刷 java描述（26题）————Remove Duplicates from Sorted Array

╰+攻爆jí腚メ 2022-03-25 06:22 276阅读 0赞

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

Given a sorted array *nums*, remove the duplicates [**in-place**][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 by **modifying the input array [in-place][]** with O(1) extra memory.

**Example 1:**

Given 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 returned length.

从有序数组中删除重复的序列并返回最终数组的长度

这个问题的结题思路是这样的

先设置一个长度 length = nums.length

将数组的第一个元素与下一个元素比较，若相同则利用算法将下一个元素删除并且指针不变，length-1，否则若不同则指针移向下一位，直到遍历完整个数组

另一个算法是比较快的

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

[in-place]: https://en.wikipedia.org/wiki/In-place_algorithm