lc-26

//Given an integer array nums sorted in non-decreasing order, remove the duplica
//tes in-place such that each unique element appears only once. The relative order
// of the elements should be kept the same. 
//
// Since it is impossible to change the length of the array in some languages, y
//ou must instead have the result be placed in the first part of the array nums. M
//ore formally, if there are k elements after removing the duplicates, then the fi
//rst k elements of nums should hold the final result. It does not matter what you
// leave beyond the first k elements. 
//
// Return k after placing the final result in the first k slots of nums. 
//
// Do not allocate extra space for another array. You must do this by modifying 
//the input array in-place with O(1) extra memory. 
//
// Custom Judge: 
//
// The judge will test your solution with the following code: 
//
// 
//int[] nums = [...]; // Input array
//int[] expectedNums = [...]; // The expected answer with correct length
//
//int k = removeDuplicates(nums); // Calls your implementation
//
//assert k == expectedNums.length;
//for (int i = 0; i < k; i++) {
//    assert nums[i] == expectedNums[i];
//}
// 
//
// If all assertions pass, then your solution will be accepted. 
//
// 
// Example 1: 
//
// 
//Input: nums = [1,1,2]
//Output: 2, nums = [1,2,_]
//Explanation: Your function should return k = 2, with the first two elements of
// nums being 1 and 2 respectively.
//It does not matter what you leave beyond the returned k (hence they are unders
//cores).
// 
//
// Example 2: 
//
// 
//Input: nums = [0,0,1,1,1,2,2,3,3,4]
//Output: 5, nums = [0,1,2,3,4,_,_,_,_,_]
//Explanation: Your function should return k = 5, with the first five elements o
//f nums being 0, 1, 2, 3, and 4 respectively.
//It does not matter what you leave beyond the returned k (hence they are unders
//cores).
// 
//
// 
// Constraints: 
//
// 
// 1 <= nums.length <= 3 * 104 
// -100 <= nums[i] <= 100 
// nums is sorted in non-decreasing order. 
// 
// Related Topics Array Two Pointers 
// 👍 7035 👎 10653


//leetcode submit region begin(Prohibit modification and deletion)
class Solution {
    public int removeDuplicates(int[] nums) {
        if (nums == null || nums.length == 0) {
            return 0;
        }
        
        int curV = Integer.MAX_VALUE;
       	int index = -1;
        
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] != curV) {
                curV = nums[i];
                index++;
                nums[index] = curV;
            }
        }
        
        return index + 1;
    }
}
//leetcode submit region end(Prohibit modification and deletion)