【Leetcode】26. Remove Duplicates from Sorted Array
26.Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/)
Easy
Given a sorted array nums, remove the duplicates in-place such that each element appear only onceand return the new length.
Do not allocate extra space for another array, you must do this by modifying the input array in-placewith 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.
已排好序的数组，只能 in place 替换，不能用额外数组，并且要求结果返回unique的长度。
题解
方法是双指针，一个指针只记录unique的并且帮助记录长度，一个指针往前找。
class Solution {
public int removeDuplicates(int[] A) {
if(A == null || A.length==0) return 0;
int len=1;
int n = A.length;
for(int i=1; i<n; i++) {
if(A[i] != A[i-1]) {
if(A[i] != A[len])
A[len] = A[i];
len++;
}
}
return len;
}
}
Runtime: 10 ms, faster than 38.40% of Java online submissions for Remove Duplicates from Sorted Array.
