Find Minimum Operations to Make All Elements Divisible by Three

Problem Description

So, you’ve got a bunch of numbers, and you want to make them all divisible by three. Sounds simple, right? Well, it’s like trying to get your cat to take a bath—easier said than done! The task is to find the minimum number of operations required to make all elements in an array divisible by three.

Imagine you’re at a party, and everyone is dancing. But wait! Some people are doing the cha-cha while others are doing the robot. You need to get everyone to do the same dance (the “divisible by three” dance) with the least amount of effort.

In this problem, you can perform operations on the numbers, but only if they’re not already divisible by three. So, let’s dive into the code!

Code Solution


class Solution {
  public int minimumOperations(int[] nums) {
    return (int) Arrays.stream(nums).filter(num -> num % 3 != 0).count();
  }
}

Approach

The approach here is as straightforward as it gets. We’re using Java Streams to filter out the numbers that are not divisible by three and then counting them. The result is the minimum number of operations needed to make all elements divisible by three. It’s like counting how many people at the party are still doing the cha-cha!

Time and Space Complexity

Complexity Type	Complexity
Time Complexity	O(n), where n is the number of elements in the array. We traverse the array once to filter and count.
Space Complexity	O(1), as we are not using any additional data structures that grow with the input size.

Real-World Example

Let’s say you’re organizing a pizza party, and you have a variety of pizzas with different toppings. You want to make sure that every pizza has a topping that is divisible by three (because, you know, three is a magic number!). If you have 10 pizzas, and 4 of them have toppings that aren’t divisible by three, you’ll need to change those 4 pizzas. That’s your answer!