Go Coding with Asparagos: Can Two Chefs Make Twin Salads?

Hi! I'm Asparagos — an asparagus who codes in Go. Here you’ll find everyday problems that a typical veggie might struggle with — and my Go solutions to them. Today we are solving the problem of Twin salads 🥗.

Two chefs. One line of veggies. Can they make identical salads?

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Problem

There are two chefs who have to prepare twin salads. In front of them lies a straight line of vegetables, arranged in a row. The chefs are standing on opposite ends of this line.

Each time, both chefs pick one vegetable — the one closest to them — and add it to their salad. Obviously, the order in which the vegetables are added is crucial (you know, when a cucumber joins a close-knit team of tomato and pepper, it's not the same as when the pepper crashes the cucumber-tomato party).

If, in the end, there’s only one vegetable left in the middle, the chefs can split it evenly between themselves. If there are no vegetables at all, the salads can be considered as twins.

The question is: are the chefs able to make identical salads?

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Input 🥦

A slice of strings — each string represents a vegetable.

Case doesn't matter: it doesn't matter whether you call yourself Broccoli or BrOcCoLi — you're just a broccoli.

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Examples 🥒:

• Example 1

  Input: ["cucumber", "tomato", "pepper", "pepper", "tomato", "cucumber"]

  Output: true

• Example 2

  Input: ["cucumber", "tomato", "pepper", "lettuce"]

  Output: false

• Example 3

  Input: ["cucumber", "tomato", "cucumber", "tomato"]

  Output: false

• Example 4

  Input: []

  Output: true

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Solution 💡

1. First of all, if the input has 0 or 1 elements, the salads are automatically identical, and there's nothing else to check.

2. We can make twin salads if the first vegetable is the same as the last, the second is the same as the second to last, and so on.

   We'll use two indices leftInd and rightInd.
   leftInd points to the vegetable that the first chef should pick up next.
   rightInd points to the vegetable that the second chef should pick up next.

   The first chef goes from left to right, so leftInd will be increased at each iteration. The second chef goes from right to left, so rightInd will be decreased.

3. At each iteration we check if the vegetables are equal. We use strings.ToLower(), because case doesn't matter.

   If the left and right vegetables are not equal, it means we can't make identical salads.

   And if we've checked all the pairs without finding any differences, we can be sure that salads are twins.
   

func areSaladsTwin(vegetables []string) bool {
    if len(vegetables) < 2 {
        return true
    }
    leftInd := 0
    rightInd := len(vegetables) - 1
    for leftInd < rightInd {
        if strings.ToLower(vegetables[leftInd]) != strings.ToLower(vegetables[rightInd]) {
            return false
        }
        leftInd++
        rightInd--
    }
    return true
}

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Feel free to check out the full code with tests on GitHub, and don’t hesitate to leave a ⭐ if you find it helpful!