反向Swift字典查找

func reverseLookup(dictionary: [String: String], value: String) -> [String] {
    var keys: [String] = []
    for (key, val) in dictionary {
        if val == value {
            keys.append(key)
        }
    }
    return keys
}

let dict = ["A": "Apple", "B": "Banana", "C": "Apple", "D": "Cherry"]
let keys = reverseLookup(dictionary: dict, value: "Apple")
print(keys) // Output: ["A", "C"]

func reverseLookup(dictionary: [String: String], value: String) -> [String] {
    let reversedDictionary = Dictionary(uniqueKeysWithValues: dictionary.lazy.map({ ($1, $0) }))
    let keys = reversedDictionary[value]
    return keys ?? []
}

let dict = ["A": "Apple", "B": "Banana", "C": "Apple", "D": "Cherry"]
let keys = reverseLookup(dictionary: dict, value: "Apple")
print(keys) // Output: ["A", "C"]