LeetCode之Peak Index in a Mountain Array（Kotlin）

weixin_34051201

于 2019-01-01 07:21:30 发布

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文章标签：数据结构与算法移动开发

原文链接：https://juejin.im/post/5c2a4058e51d451a6935dda7

本文介绍了一种算法，用于在确定为山形的数组中查找并返回顶峰元素的索引。通过遍历数组，比较每个元素与其前后的元素，找出满足山形条件的最高点。

问题： Let's call an array A a mountain if the following properties hold: A.length >= 3 There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1] Given an array that is definitely a mountain, return any i such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1].

方法：遍历数组，找到山峰所在的index输出即可。

具体实现：

class PeakIndexInAMountainArray {
    fun peakIndexInMountainArray(A: IntArray): Int {
        var peakIndex = 0
        for (i in A.indices) {
            if (A[i] > A[peakIndex]) {
                peakIndex = i
            }
        }
        return peakIndex
    }
}

fun main(args: Array<String>) {
    val array = intArrayOf(0,1,0)
    val peakIndexInAMountainArray = PeakIndexInAMountainArray()
    println("result: ${peakIndexInAMountainArray.peakIndexInMountainArray(array)}")
}
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有问题随时沟通

具体代码实现可以参考Github