hello-algo/en/codes/swift/chapter_searching/hashing_search.swift

51 lines
1.5 KiB
Swift

/**
* File: hashing_search.swift
* Created Time: 2023-01-28
* Author: nuomi1 (nuomi1@qq.com)
*/
import utils
/* Hash search (array) */
func hashingSearchArray(map: [Int: Int], target: Int) -> Int {
// Hash table's key: target element, value: index
// If the hash table does not contain this key, return -1
return map[target, default: -1]
}
/* Hash search (linked list) */
func hashingSearchLinkedList(map: [Int: ListNode], target: Int) -> ListNode? {
// Hash table key: target node value, value: node object
// If the key is not in the hash table, return null
return map[target]
}
@main
enum HashingSearch {
/* Driver Code */
static func main() {
let target = 3
/* Hash search (array) */
let nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8]
// Initialize hash table
var map: [Int: Int] = [:]
for i in nums.indices {
map[nums[i]] = i // key: element, value: index
}
let index = hashingSearchArray(map: map, target: target)
print("Index of target element 3 = \(index)")
/* Hash search (linked list) */
var head = ListNode.arrToLinkedList(arr: nums)
// Initialize hash table
var map1: [Int: ListNode] = [:]
while head != nil {
map1[head!.val] = head! // key: node value, value: node
head = head?.next
}
let node = hashingSearchLinkedList(map: map1, target: target)
print("The corresponding node object for target node value 3 is \(node!)")
}
}