[LeetCode]Remove Duplicates from Sorted Array II

题目：

Remove Duplicates from Sorted Array II

Follow up for "Remove Duplicates":

What if duplicates are allowed at most twice?
For example,

Given sorted array A =

[1,1,1,2,2,3]

,
Your function should return length =

5

,
and A is now

[1,1,2,2,3]

.

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

思路：

前面是删除重复所有的，这题是保留两个，想当然的做了，结果没考虑清楚，耗时不少。

C++ AC代码：

class Solution {
public:
int removeDuplicates(int A[], int n) {
if( n < 3)
return n;
int i=0, j=1,cnt = 1;
for ( ; j<n; j++){
if( A[i] == A[j] ){
if ( cnt == 1 ){
A[++i]=A[j];
}
cnt++;
}
else{
A[++i] = A[j];
cnt = 1;
}
}
return i+1;
}
};

运行时间 88ms