lintcode-easy-Remove Duplicates from Sorted Array

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于 2016-03-06 07:47:00 发布

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原文链接：http://www.cnblogs.com/goblinengineer/p/5246490.html

本文介绍了一个Java方法，用于去除已排序数组中的重复元素，并返回处理后的数组长度。该方法通过双指针技巧实现，不使用额外空间，在常数内存内完成操作。

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.

Do not allocate extra space for another array, you must do this in place with constant memory.

Given input array A = [1,1,2],

Your function should return length = 2, and A is now [1,2].

public class Solution {
    /**
     * @param A: a array of integers
     * @return : return an integer
     */
    public int removeDuplicates(int[] nums) {
        // write your code here
        
        if(nums == null)
            return 0;
        if(nums.length <= 1)
            return nums.length;
        
        int i = 0;
        int j = 1;
        
        while(j < nums.length){
            while(j < nums.length && nums[j] == nums[i])
                j++;
            
            if(j < nums.length){
                i++;
                nums[i] = nums[j];
            }
        }
        
        return i + 1;
    }
}