Code Solutions

removeDuplicateSortedArr.java

class Solution {
    public int removeDuplicates(int[] nums) {
       int len = nums.length; // calculate length of the array.
        
        if(len == 0 || len == 1)return len; // return length if array has  zero or only one element.
        
        int lastMem =  nums[0]; // stores the element that is not duplicate
        int count = 1; //return count at last so as to get the unique element count
        int index = 1;  
      
      /* Traverse the array from first to last and swap the element which is unique with the element in starting and increase the index.
      */
        
        for (int i=1; i < len;i++){
            if(nums[i] != lastMem){ 
                lastMem = nums[i];
                nums[index++] = lastMem;
                count++;               
            }
        }
        
        return count;
    }
}

public int removeDuplicates(int[] nums) {
    if (nums.length == 0) return 0;
    int i = 0;
    for (int j = 1; j < nums.length; j++) {
        if (nums[j] != nums[i]) {
            i++;
            nums[i] = nums[j];
        }
    }
    return i + 1;
}