leetcode--Remove Duplicates from Sorted Array II

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 ofnums being 1, 1, 2, 2 and3. It doesn't matter what you leave beyond the new length.

题意：移除排序数组中的重复元素，一个元素最多出现两次

分类：数组，双指针

解法1：和leetcode--Remove Duplicates from Sorted Array一样，使用双指针，但是每次覆盖时，判断是否由两个以上重复，如果是，覆盖两次，否则覆盖一次

[java]  view plain  copy

1. public class Solution {  
2.    public int removeDuplicates(int[] nums) {  
3.         int cur = Integer.MIN_VALUE;  
4.         int count = 0;  
5.         int sum = 0;  
6.         for(int i=0;i<nums.length;i++){  
7.             if(cur==nums[i]){  
8.                 if(count==1){  
9.                     nums[sum] = nums[i];   
10.                     count++;  
11.                     sum++;                    
12.                 }else{                        
13.                     count = 0;  
14.                     cur = nums[i];                    
15.                 }  
16.             }else{  
17.                 cur = nums[i];  
18.                 nums[sum] = nums[i];   
19.                 sum++;  
20.                 count = 1;  
21.             }             
22.         }  
23.         return sum;  
24.     }  
25.   
26. }  

[java]  view plain  copy

1. public class Solution {  
2.     public int removeDuplicates(int[] nums) {  
3.         int count = 0;  
4.         int len = nums.length;  
5.         if(len==0) return 0;  
6.         int pre = 0;  
7.         int cur = 0;  
8.         while(cur<len){  
9.             if(nums[cur]==nums[pre]){  
10.                 cur++;  
11.             }else{  
12.                 nums[count++] = nums[pre];  
13.                 if(cur-pre>=2){  
14.                     nums[count++] = nums[pre];  
15.                 }  
16.                 pre = cur;  
17.             }  
18.         }  
19.         nums[count++] = nums[cur-1];  
20.         if(cur-pre>=2){  
21.             nums[count++] = nums[cur-1];  
22.         }  
23.         return count;  
24.     }  
25. }  

原文链接http://blog.youkuaiyun.com/crazy__chen/article/details/46425475