全ての記事

leetcode war 27 - Remove Element

2017-10-29 @sunderls

leetCode js

https://leetcode.com/problems/remove-element/description/

Given an array and a value, remove all instances of that value in place and return the new length.

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

The order of elements can be changed. It doesn't matter what you leave beyond the new length.

Example: Given input array nums = [3,2,2,3], val = 3

Your function should return length = 2, with the first two elements of nums being 2.

analysis

this is very similar to the last problem leetcode war 26 - Remove Duplicates from Sorted Array, so the solution seems very straight forward.

code

/**
 * @param {number[]} nums
 * @param {number} val
 * @return {number}
 */
var removeElement = function(nums, val) {
    nums.push(null);
    var current = nums.shift();
    while (current !== null) {
        if (current !== val) {
            nums.push(current);
        }
        current = nums.shift();
    }
    return nums.length;  
};

it just passed, but ranked very slow, only top 60%.