80. Remove Duplicates from Sorted Array II

题目描述

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.

思路

筛选重复的，最多留下两个。后一个与前面一个比，相同就让后一个加入，不相同也是让后一个加入。这样就实现每个值最多出现两次。

class Solution {
public:
    int removeDuplicates(vector<int>& A) {
        int n = A.size();
        int j = 0, t = 1;
        int count = 1;
        if(n == 0)
            return 0;
        if(n == 1)
        return 1;
        A[0] = A[0];
        for(int i = 1; i < n; i++, j++)
        {
            if(A[i] == A[j] && count < 2)
            {
                A[t++] = A[i];
                count++;
            }
            else if(A[i] != A[j]) 
            {
                A[t++] = A[i];
                count = 1;
            }
        }
        /*for(i = 0; i < t; i++)
            cout<<A[i]<<" ";*/
        return t;
    }
};