LeetCode14.最长公共前缀(Kotlin语言)

class Solution {
    fun longestCommonPrefix(strs: Array<String>): String {
        if (strs.isEmpty()) return ""

        // 数组中的最短的字符串长度
        var shortestStrLen = Int.MAX_VALUE
        strs.forEach {
            shortestStrLen = Math.min(it.length, shortestStrLen)
        }
        if (shortestStrLen == 0) return ""

        val n = strs.size
        var maxCommonLen = 0

        var flag = true
        for (len in 0 until shortestStrLen) {
            for (i in 1 until n) {
                if (strs[i][len] != strs[0][len]) {
                    flag = false
                    break
                }
            }

            // 遍历中断
            if (!flag) {
                maxCommonLen = len
                break
            } else {
                // 全部遍历均相同
                maxCommonLen = shortestStrLen
            }
        }

        return strs[0].subSequence(0, maxCommonLen).toString()
        
    }
}

fun main() {
    run {
        val strs = arrayOf("flower", "flow", "flight")
        val common = longestCommonPrefix(strs)
        println("common=$common, expected=fl")
    }

    run {
        val strs = arrayOf("dog", "racecar", "car")
        val common = longestCommonPrefix(strs)
        println("common=$common, expected=")
    }

    run {
        val strs = arrayOf("doger", "dogeracecar", "dogercar")
        val common = longestCommonPrefix(strs)
        println("common=$common, expected=doger")
    }

    run {
        val strs = arrayOf("abca", "aba", "aaab")
        val common = longestCommonPrefix(strs)
        println("common=$common, expected=a")
    }

    run {
        val strs = arrayOf("c", "acc", "ccc")
        val common = longestCommonPrefix(strs)
        println("common=$common, expected=")
    }

    run {
        val strs = arrayOf("aac", "acab", "aa", "abba", "aa")
        val common = longestCommonPrefix(strs)
        println("common=$common, expected=a")
    }
}

// 输出:
common=fl, expected=fl
common=, expected=
common=doger, expected=doger
common=a, expected=a
common=, expected=
common=a, expected=a