检查Swift中两个字符串表达式之间的相似性

func levenshteinDistance(_ s1: String, _ s2: String) -> Int {
    let s1 = Array(s1)
    let s2 = Array(s2)
    var distances = Array(repeating: Array(repeating: 0, count: s2.count + 1), count: s1.count + 1)

    for i in 0...s1.count {
        distances[i][0] = i
    }
    for j in 0...s2.count {
        distances[0][j] = j
    }

    for (i, c1) in s1.enumerated() {
        for (j, c2) in s2.enumerated() {
            let cost = (c1 == c2) ? 0 : 1
            distances[i + 1][j + 1] = min(distances[i][j + 1] + 1, distances[i + 1][j] + 1, distances[i][j] + cost)
        }
    }

    return distances[s1.count][s2.count]
}

let str1 = "kitten"
let str2 = "sitting"
let distance = levenshteinDistance(str1, str2)
print("The Levenshtein distance between \"\(str1)\" and \"\(str2)\" is \(distance).")