How to implement a memoization table using a map in Go?

To implement a memoization table using a map in Go, you can follow these steps:

Create a global map variable to serve as the memoization table. The key of the map will be the input value, and the value will be the computed result. You can use any appropriate data type for the keys and values.

var memoTable = make(map[Key]Value)

Define the struct types for the key and value. These should be comparable types that can be used as keys in a map.

type Key struct {
    // Define the fields for the key type
}

type Value struct {
    // Define the fields for the value type
}

Implement a function that performs the computation you want to memoize. This function should take the necessary input and return the computed result.

func Compute(key Key) Value {
    // Implement the computation logic and return the result
}

Write a wrapper function that checks the memoization table before calling the computation function. If the result for a given key is already present in the table, return it. Otherwise, compute the result and store it in the table.

func GetComputedValue(key Key) Value {
    if result, ok := memoTable[key]; ok {
        return result
    }

    result := Compute(key)
    memoTable[key] = result
    return result
}

Now you can call the GetComputedValue function whenever you want to compute a value. It will retrieve the result from the memoization table if available, or compute and store it otherwise.

Note: You should be careful when using a global map for memoization, as it is not thread-safe. If concurrent access is a concern, you can use a concurrent map package like sync.Map to handle safe access to the memoization table.