Delete any number of sorting an array of repeating numbers

Disclaimer: This article is a blogger original article, shall not be reproduced without the bloggers allowed. https://blog.csdn.net/weixin_39675633/article/details/89463242

Delete any number of sorting an array of repeating numbers

problem

Given the array is sorted, remove duplicates, so that each element is present only dup_count and returns the new length.

• For example: dup_count = 1, known as the array input array A [1, 1, 2], the output of A [1, 2]
• For example: dup_count = 2, the input array is known array A [1, 1, 1, 2, 2, 3], the output of A [1, 1, 2, 2, 3]
• For example: dup_count = 3, the input array is known array A [1, 1, 1, 1, 2, 2, 3, 3, 3, 4, 4, 5], the output of A [1, 1, 1, 2 , 2, 3, 3, 3, 4, 4, 5]

void print(std::vector<int>& nums, const std::string& note)
{
  std::cout << std::endl << note << std::endl;
  for (int i = 0; i < nums.size(); ++i)
  {
    std::cout << nums[i] << ", ";
  }
  std::cout << std::endl;
}

int removeDuplicatesElem(std::vector<int>& nums, int dup_count = 2)
{
  if (nums.size() <= dup_count) 
    return nums.size();

  int index = dup_count;
  for (int i = index; i < nums.size(); ++i)
  {
    if (nums[i] != nums[index - dup_count]) 
    {
      nums[index++]  = nums[i];
    }
  }
  return index;
}

int main(int argc, char** argv)
{
  if (argc != 2)
  {
    std::cerr << "Uage: ./demo dup_count" << std::endl;
    return 1;
  }
  int dup_count = std::stoi(std::string(argv[1]));

  std::cout << "please input a sorted array(int ): " << std::endl;
  int elem;
  std::vector<int> nums;
  while (std::cin >> elem)
  {
    nums.push_back(elem); 
  }

  print(nums, "output origen array:");

  int n = removeDuplicatesElem(nums, dup_count);

  for (int i = 0; i < n; i++)
    std::cout << nums[i] << ", ";
  std::cout << std::endl;
  
  return 0;
}