LeetCode算法入门- Remove Duplicates from Sorted Array -day21
- 题目描述
Given a sorted array nums, 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 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.
Example 2:
Given nums = [0,0,1,1,1,2,2,3,3,4],
Your function should return length = 5, with the first five elements of nums being modified to 0, 1, 2, 3, and 4 respectively.
It doesn’t matter what values are set beyond the returned length.
-
题目分析
将一个数组重复的元素去掉，并返回数组长度。 -
Java实现
定义两个指针，i指针从0开始，j从1开始，如果nums[i]与nums[j]相等，则j向后移动，移到nums[i]与nums[j]不相等，这是才将
nums[++i] = nums[j]，最后返回i+1.
class Solution {public int removeDuplicates(int[] nums) {if(nums.length == 0) return 0;int i = 0;for(int j = 1; j < nums.length; j++){if(nums[j] != nums[i]){i++;nums[i] = nums[j];}}return i+1;}
}
 -day22)
