How is a hash table structured? What are the basic principles embedded in it, and the main requirements?

A hash table is a data structure that provides fast access to elements by key. The main principle is using a hash function to convert the key into an array index where the value is stored.

Basic principles:

• Hash function: converts the key into an integer index.
• Collision resolution: since different keys can have the same index, methods such as chaining (linked lists) or open addressing are used.
• Dynamic resizing: when a certain load factor is reached, the table is expanded to maintain efficiency.

Main requirements:

• A fast and uniform hash function that minimizes collisions.
• Efficient collision resolution.
• Support for insert, search, and delete operations with an amortized complexity close to O(1).

Example in Go (simplified):

Type HashTable struct {
    buckets [][]KeyValue
}

type KeyValue struct {
    key string
    value interface{}
}

func (ht *HashTable) hash(key string) int {
    var hash int
    for _, c := range key {
        hash = 31*hash + int(c)
    }
    return hash % len(ht.buckets)
}

func (ht *HashTable) Put(key string, value interface{}) {
    index := ht.hash(key)
    // add or update in chain
}

func (ht *HashTable) Get(key string) (interface{}, bool) {
    index := ht.hash(key)
    // search in chain
    return nil, false
}

This is a basic example; real implementations consider resizing, deletion, and optimizations.