26. Remove Duplicates from Sorted Array
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.
難度：easy
題目：給定一排序陣列，原地移除重複的元素並返回新陣列長度且每個元素只出現一次。不要重新分配額外的空間，必須原地修改給出的陣列。
思路：用一變數記錄置換元素的下標。
Runtime: 6 ms, faster than 99.11% of Java online submissions for Remove Duplicates from Sorted Array.
Memory Usage: 26.6 MB, less than 95.90% of Java online submissions for Remove Duplicates from Sorted Array.
class Solution {
public int removeDuplicates(int[] nums) {
if (nums.length <= 1) {
return nums.length;
}
int idx = 1;
for (int i = 1; i < nums.length; i++) {
if (nums[i] != nums[i - 1]) {
nums[idx++] = nums[i];
}
}
return idx;
}
}