LeetCode - Algorithms - 26. Remove Duplicates from Sorted Array

Java

The size of a Java array is fixed when you allocate it, and cannot be changed.

You’ve to provide a fixed size for that Array, You can neither EXPAND or SHRINK that array.

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26.[圖解]Remove Duplicates from Sorted Array

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class Solution {
    public int removeDuplicates(int[] nums) {
    	if (nums.length<2) return nums.length;
    	int x=0,y=1;
    	while (y<nums.length) {
    		if (nums[x]==nums[y]) {
    			y+=1;
    		}
    		else {
    			x+=1;
    			nums[x]=nums[y];
    			y+=1;
    		}
    	}
        return x+1;        
    }
}

Submission Detail

  • 161 / 161 test cases passed.
  • Runtime: 6 ms
  • Memory Usage: 39.8 MB
  • Your runtime beats 97.51 % of java submissions.

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5 lines Java solution

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

Submission Detail

  • 161 / 161 test cases passed.
  • Runtime: 7 ms
  • Memory Usage: 42 MB
  • Your runtime beats 61.11 % of java submissions.

JavaScript

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/**
 * @param {number[]} nums
 * @return {number}
 */
var removeDuplicates = function(nums) {
    if (nums.length < 2) return nums.length;
    for (var i = 0; i < nums.length; i++) {
        while (nums[i] === nums[i-1]) 
            nums.splice(i, 1);
    }
    return nums.length;    
};

Submission Detail

  • 161 / 161 test cases passed.
  • Runtime: 84 ms, faster than 42.35% of JavaScript online submissions for Remove Duplicates from Sorted Array.
  • Memory Usage: 37.7 MB, less than 22.92% of JavaScript online submissions for Remove Duplicates from Sorted Array.

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