Remove Duplicates from Sorted Array II Solutions in C++

// Source : https://oj.leetcode.com/problems/remove-duplicates-from-sorted-array-ii/
// Author : Hao Chen
// Date   : 2014-06-29



#include <stdio.h>


int removeDuplicates(int A[], int n) {
    if (n<=2) return n;
    int pos=0;
    int cnt=1;
    for (int i=1; i<n; i++){
        if (A[i] == A[pos]){
            cnt++;
            if (cnt==2){
                A[++pos] = A[i];
            }
        }else{
            cnt=1;
            A[++pos] = A[i];
            
        }
    } 
    return pos+1;
}

void printfArray(int A[], int n) {
    printf("{ ");
    for (int i=0; i<n; i++){
        printf("%d ", A[i]);
    }
    printf("}\n");
}


void testSuite(int a[], int n){
    printfArray(a, n);
    n = removeDuplicates(a, n);
    printfArray(a, n);
    printf("------------------\n");
}

#define TEST(a) testSuite(a, sizeof(a)/sizeof(int))
int main()
{
    int a0[] = {1, 2, 3, 4, 5};
    TEST(a0);
    int a1[] = {1, 1, 1};
    TEST(a1);
    int a2[] = {1, 2, 2};
    TEST(a2);
    int a3[] = {1, 1, 2};
    TEST(a3);
    int a4[] = {1, 1, 1, 1};
    TEST(a4);
    int a5[] = {1, 1, 1, 2};
    TEST(a5);
    int a6[] = {1, 2, 2, 2};
    TEST(a6);
    int a7[] = {1, 2, 2, 2, 3 };
    TEST(a7);
    int a8[] = {1, 2, 2, 2, 3, 3};
    TEST(a8);
    int a9[] = {1,1,1,2,2,3};
    TEST(a9);
    int a10[] = {1,1,1,2,2,2};
    TEST(a10);
    int a11[] = {1,1,1,1,3,3};
    TEST(a11);
    return 0;
}

class Solution {
public:
    int removeDuplicates(int A[], int n) {
        if (n<3) return n;
        int size{1};
        for (int i=2; i<n; ++i)
            if (A[i] != A[size] || A[i] != A[size-1])
                A[++size] = A[i];
        return ++size;
    }
};

/// Source : https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/description/
/// Author : liuyubobobo
/// Time   : 2016-12-26
#include <iostream>
#include <vector>

using namespace std;

/// Ad-Hoc
/// Time Complexity: O(n)
/// Space Complexity: O(1)
class Solution {
public:
    int removeDuplicates(vector<int>& nums) {

        int i = 0;
        int j = 0;
        while(j < nums.size()){
            int k = nextIndex(nums, j);
            int len = min( 2, k-j);
            for(int ii = 0 ; ii < len ; ii ++)
                nums[i+ii] = nums[j];
            i += len;
            j = k;
        }

        return i;
    }

private:
    int nextIndex(const vector<int>& nums, int index){
        for(int i = index ; i < nums.size() ; i ++)
            if(nums[i] != nums[index])
                return i;
        return nums.size();
    }
};


int main() {

    vector<int> nums1 = {1, 1, 1, 2, 2, 3};
    cout << Solution().removeDuplicates(nums1) << endl;

    return 0;
}