1、简单的快速排序+二分查找

package main

import "fmt"

// 快速排序+二分查找

// 快速排序
func QuickSort(arr []int) []int {
    length := len(arr)
    if length <= 1 {
        return arr
    } else {
        spiltData := arr[0]
        low := make([]int, 0, 0)
        mid := make([]int, 0, 0)
        higth := make([]int, 0, 0)

        //mid = append(mid, spiltData)
        for i:=0; i<length; i++ {
            if arr[i] > spiltData {
                higth = append(higth, arr[i])
            } else if arr[i] < spiltData {
                low = append(low, arr[i])
            } else {
                mid = append(mid, arr[i])
            }
        }

        higth, low = QuickSort(higth), QuickSort(low)
        return  append(append(low, mid...), higth...)
    }
}

// 二分查找
func binSearch(arr []int, data int) int {
    low, hight := 0, len(arr)-1 // 找到最左和最右下标
    for low <= hight {
        mid := (low + hight)/2
        if data > arr[mid] {
            low = mid + 1
        } else if data < arr[mid] {
            hight = mid - 1
        } else {
            return mid
        }
    }
    return -1
}

func main()  {
    arr := []int{2, 3, 1, 5, 3, 7, 0}
    fmt.Println("未排序：", arr)
    arr1 := QuickSort(arr)
    fmt.Println("排序后：", arr1)
    index := binSearch(arr1, 7)
    if index == -1 {
        fmt.Println("没找到！")
    } else {
        fmt.Printf("找到数据%d, 下标为%d。", arr1[index], index)
    }
}