How to Remove all occurrence of certain number ?

[Question]: Given an integer array nums and an integer k, remove all occurrences of k in nums in-place. The order of the elements may be changed. Then return the count after removal


We can declare a variable which holds index initial it’s 0 now move elements which are not matched with k

// TC: O(n)
// SC: O(1)
func removeElement(_ nums: inout [Int], _ val: Int) -> Int {
    var count = 0
    for i in 0..<nums.count where nums[i] != val {
        nums[count] = nums[i]
    return count
var arrOcc = [0,1,2,2,3,0,4,2]
removeElement(&arrOcc, 2)
//print("Output after removal --", arrOcc)//[0, 1, 3, 0, 4, 0, 4, 2]

Leave a Comment

Your email address will not be published. Required fields are marked *