26. Remove Duplicates from Sorted Array

https://leetcode.com/problems/remove-duplicates-from-sorted-array/

C++

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if (nums.empty()) {
            return 0;
        }
        int prev = 0;
        int current = 1;
        while (current < nums.size()) {
            if (nums[prev] != nums[current]) {
                nums[++prev] = nums[current];
            }
            current++;
        }
        return prev + 1;
    }
};

Go

func removeDuplicates(nums []int) int {
    if len(nums) == 0 {
        return 0
    }
    prev := 0
    current := 1
    for current < len(nums) {
        if nums[prev] != nums[current] {
            prev++
            nums[prev] = nums[current]
        }
        current++
    }
    return prev+1
}

JavaScript

/**
 * @param {number[]} nums
 * @return {number}
 */
var removeDuplicates = function(nums) {
  if (!nums || !nums.length) {
    return 0
  }

  var prev = 0
  var current = 1

  while (current < nums.length) {
    if (nums[prev] !== nums[current]) {
      nums[++prev] = nums[current]
    }
    current++
  }

  return prev + 1
}

Python

class Solution(object):

    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        if not nums:
            return 0

        prev, current = 0, 1
        while current < len(nums):
            if nums[prev] != nums[current]:
                prev += 1
                nums[prev] = nums[current]
            current += 1

        return prev + 1