go count distinct elements in list

To count the distinct elements in a list using the Go programming language, you can follow these steps:

1. Create a map with the elements of the list as keys and their counts as values. This map will help us keep track of the distinct elements and their occurrences in the list.

2. Iterate over each element in the list using a loop. For each element, check if it already exists as a key in the map.

3. If the element exists as a key in the map, increment its corresponding value by 1.

4. If the element does not exist as a key in the map, add it as a new key with an initial count of 1.

5. After iterating over all the elements in the list, the map will contain all the distinct elements as keys and their respective counts as values.

6. Finally, calculate the total count of distinct elements by finding the length of the map using the len() function.

Here is an example code snippet that demonstrates the steps mentioned above:

package main

import "fmt"

func countDistinctElements(list []int) int {
    elementCount := make(map[int]int)

    for _, element := range list {
        if _, exists := elementCount[element]; exists {
            elementCount[element]++
        } else {
            elementCount[element] = 1
        }
    }

    return len(elementCount)
}

func main() {
    list := []int{1, 2, 3, 4, 4, 3, 2, 1, 5, 6, 7, 8, 9, 9, 8, 7, 6, 5}
    distinctCount := countDistinctElements(list)

    fmt.Println("Total distinct elements:", distinctCount)
}

In this example, the list contains 18 elements, but only 9 of them are distinct. The program outputs "Total distinct elements: 9".