// File: array_hash_map.go // Created Time: 2022-12-14 // Author: msk397 (machangxinq@gmail.com) package chapter_hashing import "fmt" /* Key-value pair */ type pair struct { key int val string } /* Hash table based on array implementation */ type arrayHashMap struct { buckets []*pair } /* Initialize hash table */ func newArrayHashMap() *arrayHashMap { // Initialize an array, containing 100 buckets buckets := make([]*pair, 100) return &arrayHashMap{buckets: buckets} } /* Hash function */ func (a *arrayHashMap) hashFunc(key int) int { index := key % 100 return index } /* Query operation */ func (a *arrayHashMap) get(key int) string { index := a.hashFunc(key) pair := a.buckets[index] if pair == nil { return "Not Found" } return pair.val } /* Add operation */ func (a *arrayHashMap) put(key int, val string) { pair := &pair{key: key, val: val} index := a.hashFunc(key) a.buckets[index] = pair } /* Remove operation */ func (a *arrayHashMap) remove(key int) { index := a.hashFunc(key) // Set to nil, representing removal a.buckets[index] = nil } /* Retrieve all key pairs */ func (a *arrayHashMap) pairSet() []*pair { var pairs []*pair for _, pair := range a.buckets { if pair != nil { pairs = append(pairs, pair) } } return pairs } /* Get all keys */ func (a *arrayHashMap) keySet() []int { var keys []int for _, pair := range a.buckets { if pair != nil { keys = append(keys, pair.key) } } return keys } /* Get all values */ func (a *arrayHashMap) valueSet() []string { var values []string for _, pair := range a.buckets { if pair != nil { values = append(values, pair.val) } } return values } /* Print hash table */ func (a *arrayHashMap) print() { for _, pair := range a.buckets { if pair != nil { fmt.Println(pair.key, "->", pair.val) } } }