LeetCode之Remove Duplicates from Sorted Array II

1、題目

Follow up for "Remove Duplicates":

What if duplicates are allowed at most twice?

For example,

Given sorted array nums = [1,1,1,2,2,3],

Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3. It doesn't matter what you leave beyond the new length.

2、代碼實作

public class Solution {

   public int removeDuplicates(int[] nums) {

    if (null == nums || nums.length == 0) {

     return 0;

    }

    int length = nums.length;

    int newLen = 1;

    int count = 1;

    for (int i = 1; i < length; ++i) {

     if (nums[i] == nums[i - 1]) {

      count++;

      if (count <= 2) {

       nums[newLen++] =  nums[i];

      }

     } else {

      count = 1;

      nums[newLen++] = nums[i];

     }

       return newLen;

   }

}

3、總結

既然看到連續相等，那我們就要想到前後兩個不相等作為條件，然後加上通過一個變量不超過2個就可以了