LCR041-MovingAverageFromDataStream.go

package main

// LCR 041. 数据流中的移动平均值
// 给定一个窗口大小和一个整数数据流，根据该滑动窗口的大小，计算滑动窗口里所有数字的平均值。
// 实现 MovingAverage 类：
//     MovingAverage(int size) 
//         用窗口大小 size 初始化对象。
//     double next(int val) 
//         成员函数 next 每次调用的时候都会往滑动窗口增加一个整数，
//         请计算并返回数据流中最后 size 个值的移动平均值，即滑动窗口里所有数字的平均值。

// 示例：
// 输入：
// inputs = ["MovingAverage", "next", "next", "next", "next"]
// inputs = [[3], [1], [10], [3], [5]]
// 输出：
// [null, 1.0, 5.5, 4.66667, 6.0]
// 解释：
// MovingAverage movingAverage = new MovingAverage(3);
// movingAverage.next(1); // 返回 1.0 = 1 / 1
// movingAverage.next(10); // 返回 5.5 = (1 + 10) / 2
// movingAverage.next(3); // 返回 4.66667 = (1 + 10 + 3) / 3
// movingAverage.next(5); // 返回 6.0 = (10 + 3 + 5) / 3

// 提示：
//     1 <= size <= 1000
//     -10^5 <= val <= 10^5
//     最多调用 next 方法 10^4 次

import "fmt"

type MovingAverage struct {
    size int
    data []int
}

func Constructor(size int) MovingAverage {
    return MovingAverage{size, []int{} }
}

func (this *MovingAverage) Next(val int) float64 {
    if len(this.data) < this.size {
        this.data = append(this.data, val)
    } else {
        this.data = append(this.data[1:this.size], val)
    }
    
    sum := 0 
    for _, v := range this.data {
        sum += v
    }
    return float64(sum) / float64(len(this.data))
}

type MovingAverage1 struct {
    nums []int
    size int
    sum  int
}

/** Initialize your data structure here. */
func Constructor1(size int) MovingAverage1 {
    return MovingAverage1{size: size}
}

func (this *MovingAverage1) Next(val int) float64 {
    if len(this.nums) >= this.size {
        this.sum -= this.nums[0]
        this.nums = this.nums[1:]
    }
    this.nums = append(this.nums, val)
    this.sum += val
	return float64(this.sum) / float64(len(this.nums))
}


/**
 * Your MovingAverage object will be instantiated and called as such:
 * obj := Constructor(size);
 * param_1 := obj.Next(val);
 */

func main() {
    // MovingAverage movingAverage = new MovingAverage(3);
    obj := Constructor(3)
    fmt.Println(obj)
    // movingAverage.next(1); // return 1.0 = 1 / 1
    fmt.Println(obj.Next(1)) // 1.0
    fmt.Println(obj)
    // movingAverage.next(10); // return 5.5 = (1 + 10) / 2
    fmt.Println(obj.Next(10)) // 5.5
    fmt.Println(obj)
    // movingAverage.next(3); // return 4.66667 = (1 + 10 + 3) / 3
    fmt.Println(obj.Next(3)) // 4.66667
    fmt.Println(obj)
    // movingAverage.next(5); // return 6.0 = (10 + 3 + 5) / 3
    fmt.Println(obj.Next(5)) // 6.0
    fmt.Println(obj)

    obj1 := Constructor(4)
    fmt.Println(obj1)
    // movingAverage.next(1); // return 1.0 = 1 / 1
    fmt.Println(obj1.Next(1)) // 1.0
    fmt.Println(obj1)
    // movingAverage.next(10); // return 5.5 = (1 + 10) / 2
    fmt.Println(obj1.Next(10)) // 5.5
    fmt.Println(obj1)
    // movingAverage.next(3); // return 4.66667 = (1 + 10 + 3) / 3
    fmt.Println(obj1.Next(3)) // 4.66667
    fmt.Println(obj1)
    // movingAverage.next(5); // return 4.75= (1 + 10 + 3 + 5) / 4
    fmt.Println(obj1.Next(5)) // 4.75
    fmt.Println(obj1)

    // movingAverage.next(5); // return 5.75 = (10 + 3 + 5 + 5) / 4
    fmt.Println(obj1.Next(5)) // 5.75
    fmt.Println(obj1)


    // MovingAverage movingAverage = new MovingAverage(3);
    obj11 := Constructor1(3)
    fmt.Println(obj11)
    // movingAverage.next(1); // return 1.0 = 1 / 1
    fmt.Println(obj11.Next(1)) // 1.0
    fmt.Println(obj11)
    // movingAverage.next(10); // return 5.5 = (1 + 10) / 2
    fmt.Println(obj11.Next(10)) // 5.5
    fmt.Println(obj11)
    // movingAverage.next(3); // return 4.66667 = (1 + 10 + 3) / 3
    fmt.Println(obj11.Next(3)) // 4.66667
    fmt.Println(obj11)
    // movingAverage.next(5); // return 6.0 = (10 + 3 + 5) / 3
    fmt.Println(obj11.Next(5)) // 6.0
    fmt.Println(obj11)

    obj12 := Constructor1(4)
    fmt.Println(obj12)
    // movingAverage.next(1); // return 1.0 = 1 / 1
    fmt.Println(obj12.Next(1)) // 1.0
    fmt.Println(obj12)
    // movingAverage.next(10); // return 5.5 = (1 + 10) / 2
    fmt.Println(obj12.Next(10)) // 5.5
    fmt.Println(obj12)
    // movingAverage.next(3); // return 4.66667 = (1 + 10 + 3) / 3
    fmt.Println(obj12.Next(3)) // 4.66667
    fmt.Println(obj12)
    // movingAverage.next(5); // return 4.75= (1 + 10 + 3 + 5) / 4
    fmt.Println(obj12.Next(5)) // 4.75
    fmt.Println(obj12)

    // movingAverage.next(5); // return 5.75 = (10 + 3 + 5 + 5) / 4
    fmt.Println(obj12.Next(5)) // 5.75
    fmt.Println(obj12)
}