leetcode 26. Remove Duplicates from Sorted Array

1.题目

Given a sorted array, 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 in place with constant memory.

For example,

Given input array 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 new length.

删除数组中重复的元素并返回数组的长度。

2.思路 

直接上代码。

</pre><pre name="code" class="cpp">class Solution {
public:
int removeDuplicates(vector<int>& nums) {
//unique从输入序列中“删除”所有相邻的重复元素,其实它并不真正把重复的元素删除，是把重复的元素移到后面去了，然后依然保存到了原数组中，然后 返回去重后最后一个元素的地址

nums.erase(unique(nums.begin(),nums.end()),nums.end());
return nums.size();
};

常规解法。

class Solution {
public:
int removeDuplicates(vector<int>& nums) {

for(vector<int>::iterator it=nums.begin()+1;it!=nums.end();it)
{
if(*it==*(it-1)) nums.erase(it);
else it++;
}
return nums.size();
}
};