Linear Search

Linear Search is one of the simplest and most intuitive algorithms used to find an element in a list or array. It checks each element sequentially until the desired value is found or the list ends.

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🔍 How Linear Search Works

Given a list of elements, linear search goes from left to right, comparing each element with the target. If a match is found, it returns the index. Otherwise, it returns -1.

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📊 Example

Let's say we have the following array:

[5, 2, 9, 4, 7]

We want to search for the element 4.

Step-by-step:

1. Compare 5 with 4 → ❌
2. Compare 2 with 4 → ❌
3. Compare 9 with 4 → ❌
4. Compare 4 with 4 → ✅ Match found at index 3

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🔧 Go Implementation

Here’s a simple Go program that performs linear search:

package main

import "fmt"

func linearSearch(arr []int, target int) int {
    for i, val := range arr {
        if val == target {
            return i
        }
    }
    return -1 // Not found
}

func main() {
    nums := []int{5, 2, 9, 4, 7}
    target := 4

    index := linearSearch(nums, target)
    if index != -1 {
        fmt.Printf("Element found at index %d\n", index)
    } else {
        fmt.Println("Element not found")
    }
}

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🧪 Output

Element found at index 3

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⏱ Time and Space Complexity

Case	Time Complexity
Best Case	O(1)
Average	O(n)
Worst Case	O(n)

• Space Complexity: O(1)

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✅ When to Use Linear Search

• When the dataset is unsorted
• When the list is small
• When performance isn’t a primary concern
• When you want a quick and simple solution

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🔚 Conclusion

Linear search is a basic yet powerful algorithm, ideal for simple scenarios or when working with small, unsorted data. Though not the most efficient for large datasets, it’s a great starting point when learning how search algorithms work.

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You can view and clone the full code from my GitHub repo here: 👉 Linear Search in Go

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Happy Learning! 🚀