BST vs Hash Map Trade-offs for Ordered Data in DSA Go - Build Both Approaches

BST vs Hash Map Trade-offs for Ordered Data

📖 Scenario: Imagine you are building a simple contact list app. You want to store contacts with their phone numbers. Sometimes, you need to find a contact quickly by name. Other times, you want to list all contacts in alphabetical order.Two common ways to store this data are using a Binary Search Tree (BST) or a Hash Map. Each has its strengths and weaknesses.

🎯 Goal: Build a small program to store contacts using a map, then add a sorted list of contact names using a BST-like structure. This will help you see the difference in how data is stored and accessed.

📋 What You'll Learn

Create a map to store contact names and phone numbers.

Create a slice to hold contact names for sorting.

Sort the contact names alphabetically.

Print the contacts in alphabetical order.

💡 Why This Matters

🌍 Real World

Contact lists, phone books, and any app needing fast lookup and ordered display of data.

💼 Career

Understanding data structures like maps and trees helps in designing efficient software for search, sorting, and data management.

1

Create a map of contacts

Create a map called contacts with these exact entries: "Alice": "555-1234", "Bob": "555-5678", "Charlie": "555-8765"

DSA Go

# Create the map contacts with the given entries
# Your code here

Hint

Use map[string]string to create a map with string keys and string values.

2

Create a slice of contact names

Create a slice called names and add the keys from contacts to it using a for loop with variables name and phone iterating over contacts

DSA Go

package main

import "fmt"

func main() {
    contacts := map[string]string{
        "Alice": "555-1234",
        "Bob": "555-5678",
        "Charlie": "555-8765",
    }
    // Create a slice names and add contact names from contacts
    // Your code here
}

Hint

Use for name, phone := range contacts to loop over the map and append to add names to the slice.

3

Sort the contact names alphabetically

Import the sort package and use sort.Strings(names) to sort the names slice alphabetically

DSA Go

package main

import (
    "fmt"
    // Import sort package
)

func main() {
    contacts := map[string]string{
        "Alice": "555-1234",
        "Bob": "555-5678",
        "Charlie": "555-8765",
    }
    names := []string{}
    for name, phone := range contacts {
        _ = phone
        names = append(names, name)
    }
    // Sort the names slice alphabetically
    // Your code here
}

Hint

Use import "sort" and then call sort.Strings(names) to sort the slice.

4

Print contacts in alphabetical order

Use a for loop with variable _, name iterating over names and print each contact's name and phone number from contacts using fmt.Println(name, contacts[name])

DSA Go

package main

import (
    "fmt"
    "sort"
)

func main() {
    contacts := map[string]string{
        "Alice": "555-1234",
        "Bob": "555-5678",
        "Charlie": "555-8765",
    }
    names := []string{}
    for name, phone := range contacts {
        _ = phone
        names = append(names, name)
    }
    sort.Strings(names)
    // Print each contact name and phone number in alphabetical order
    // Your code here
}

Hint

Use for _, name := range names and print with fmt.Println(name, contacts[name]).