26. 删除有序数组中的重复项

/**
 * @param {number[]} nums
 * @return {number}
 */
var removeDuplicates = function (nums) {
  if (nums.length == 0) {
    return 0
  }
  let slow = 0,
    fast = 1
  while (fast < nums.length) {
    if (nums[fast] != nums[slow]) {
      slow = slow + 1
      nums[slow] = nums[fast]
    }
    fast = fast + 1
  }
  return slow + 1
}