Question

如果给定的数组是单调序列，我想返回true。这是我到目前为止的地方，但这个功能并没有按预期工作：

Public Class Foo
    Public Class SampleRating
        Enum SampleRateSetting As Byte
            SR0 = 1
            SR1 = 2
            SR2 = 4
            SR3 = 8
        End Enum

        Public Setting As SampleRateSetting
        Public Noise As UInt16
        Public Bandwidth As UInt16
        Public SampleRate As UInt32
        Public BinWidth As Double

        Public Shared Function FindSetting(Setting As SampleRateSetting) As Predicate(Of SampleRating)
            Return Function(Rating As SampleRating) Rating.Setting = Setting
        End Function
    End Class

    Public Shared SampleRatings As New List(Of SampleRating) From {
       New SampleRating With {.Setting = SampleRating.SampleRateSetting.SR0, .SampleRate = 100189, .BinWidth = 196, .Bandwidth = 26000, .Noise = 467},
       New SampleRating With {.Setting = SampleRating.SampleRateSetting.SR1, .SampleRate = 12524, .BinWidth = 25, .Bandwidth = 6262, .Noise = 260},
       New SampleRating With {.Setting = SampleRating.SampleRateSetting.SR2, .SampleRate = 1566, .BinWidth = 3.1, .Bandwidth = 783, .Noise = 100},
       New SampleRating With {.Setting = SampleRating.SampleRateSetting.SR3, .SampleRate = 196, .BinWidth = 0.38, .Bandwidth = 98, .Noise = 38}
   }

   ' Have also tried the below instead, with no luck
   Public Shared SampleRatings As New ReadOnlyCollection(Of SampleRating)(New List(Of SampleRating)() From {
       New SampleRating With {.Setting = SampleRating.SampleRateSetting.SR0, .SampleRate = 100189, .BinWidth = 196, .Bandwidth = 26000, .Noise = 467},
       New SampleRating With {.Setting = SampleRating.SampleRateSetting.SR1, .SampleRate = 12524, .BinWidth = 25, .Bandwidth = 6262, .Noise = 260},
       New SampleRating With {.Setting = SampleRating.SampleRateSetting.SR2, .SampleRate = 1566, .BinWidth = 3.1, .Bandwidth = 783, .Noise = 100},
       New SampleRating With {.Setting = SampleRating.SampleRateSetting.SR3, .SampleRate = 196, .BinWidth = 0.38, .Bandwidth = 98, .Noise = 38}
    })

    Function Shared Bar() As Boolean
        ' Should NOT be able to change the list or list item members here.
    End Function
End Class 'End of Foo

http://jsfiddle.net/marcusdei/t0L1wryy/6/

这不是作业，我想为我的职业生涯学习JS。谢谢！

Answer 1

您可以像$("label[for='record_type']").each(function(){ var parent = $(this).parent(); var clone = $(this).clone(); $(parent).replaceWith(clone); });一样使用{只需将every替换为[1, 2, 3, 4]）

arr

您需要调整＆gt;取决于您是否要检查单调减少/增加。

Answer 2

我只需要该功能（ES6）的高性能实现。这是我想出的：

const is_monotonically_decreasing = (array) => {
    const n = array.length
    let i = 1
    while (i < n && array[i] - array[i - 1] < 0) {
        i++
    }
    return i === n
}

这将保存第一次迭代并使用回调（较小的堆栈，较少的内存）。可以通过相应地调整array[i] - array[i - 1] < 0来更改行为。

Answer 3

JavaScript 单行解决方案：

排序和连接

var isMonotonic = (arr) => {
  return (
    arr.join`` == [...arr].sort((a, b) => a - b).join`` ||
    arr.join`` == [...arr].sort((a, b) => b - a).join``
  );
};


console.log(isMonotonic([8, 4, 2, 1]));
console.log(isMonotonic([8, 0, 5, 1]));
console.log(isMonotonic([7, 7, 7]));

每个

var isMonotonic = (arr) => {
  return (
    arr.every((v, i) => i === 0 || v <= arr[i - 1]) ||
    arr.every((v, i) => i === 0 || v >= arr[i - 1])
  );
};


console.log(isMonotonic([8, 4, 2, 1]));
console.log(isMonotonic([8, 0, 5, 1]));
console.log(isMonotonic([7, 7, 7]));

检查阵列是否处于单调序列

3 个答案:

排序和连接

每个