1
2package com.coderli.leetcode.algorithms.easy;
3
4/**
5 * Given a sorted array, remove the duplicates in place such that each element appear only once and
6 * return the new length.
7 * <p>
8 * Do not allocate extra space for another array, you must do this in place with constant memory.
9 * <p>
10 * For example,
11 * Given input array nums = [1,1,2],
12 * <p>
13 * Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively.
14 * It doesn't matter what you leave beyond the new length.
15 *
16 * @author li.hzh 2017-10-22 21:24
17 */
18public class RemoveDuplicatesFromSortedArray {
19    
20    public static void main(String[] args) {
21        RemoveDuplicatesFromSortedArray rdfSortedArray = new RemoveDuplicatesFromSortedArray();
22        System.out.println(rdfSortedArray.removeDuplicates(new int[]{1}));
23        System.out.println(rdfSortedArray.removeDuplicates(new int[]{1, 1}));
24        System.out.println(rdfSortedArray.removeDuplicates(new int[]{1, 1, 2}));
25        System.out.println(rdfSortedArray.removeDuplicates(new int[]{1, 1, 2, 2}));
26        System.out.println(rdfSortedArray.removeDuplicates(new int[]{1, 1, 1, 2, 2}));
27        System.out.println(rdfSortedArray.removeDuplicates(new int[]{1, 1, 2, 2, 3, 3}));
28        System.out.println(rdfSortedArray.removeDuplicates(new int[]{1, 2, 2, 3, 4, 4}));
29    }
30    
31    public int removeDuplicates(int[] nums) {
32        if (nums == null || nums.length == 0) {
33            return 0;
34        }
35        int compareValue = nums[0];
36        int result = 1;
37        for (int i = 1; i < nums.length; i++) {
38            if (compareValue < nums[i]){
39                compareValue = nums[i];
40                nums[result] = compareValue;
41                result++;
42            }
43        }
44        return result;
45    }
46    
47}
48