removeElement.js

//////////////////////////////////////////////Remove Element///////////////////////////////////////////////////////
// Given an integer array nums and an integer val, remove all occurrences of val in nums in-place. The relative order of the elements may be changed.
// Since it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array nums.
// More formally, if there are k elements after removing the duplicates, then the first 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 val = ...; // Value to remove
// int[] expectedNums = [...]; // The expected answer with correct length.
//                             // It is sorted with no values equaling val.
//
// int k = removeElement(nums, val); // Calls your implementation
// assert k == expectedNums.length;
// sort(nums, 0, k); // Sort the first k elements of nums
// for (int i = 0; i < actualLength; i++) {
//     assert nums[i] == expectedNums[i];
// }
// If all assertions pass, then your solution will be accepted.
// Example 1:
//
// Input: nums = [3,2,2,3], val = 3
// Output: 2, nums = [2,2,_,_]
// Explanation: Your function should return k = 2, with the first two elements of nums being 2.
// It does not matter what you leave beyond the returned k (hence they are underscores).
// Example 2:
//
// Input: nums = [0,1,2,2,3,0,4,2], val = 2
// Output: 5, nums = [0,1,4,0,3,_,_,_]
// Explanation: Your function should return k = 5, with the first five elements of nums containing 0, 0, 1, 3, and 4.
// Note that the five elements can be returned in any order.
// It does not matter what you leave beyond the returned k (hence they are underscores).
const removeElement = function(nums, val) {
    for (let i = 0; i < nums.length; i++) {
        if (nums[i] === val) {
            const temp = nums[nums.length - 1];
            nums[nums.length - 1] = nums[i];
            nums[i] = temp;
            nums.pop();
            i--;
        }
    }

    return nums.length;
};

// console.log(removeElement([3,2,2,3], 3));
// console.log(removeElement([0,1,2,2,3,0,4,2], 2));