https://www.cnblogs.com/xiaonq/p/8573587.html

01.二分查找

1.1 python

l = list(range(1,101))
def bin_search(data_set,val):
   low = 0
   high = len(data_set) - 1
   while low <= high:
      mid = (low+high)//2
      if data_set[mid] == val:
         return mid
      elif data_set[mid] < val:
         low = mid + 1
      else:
         high = mid - 1
   return
n = bin_search(l,11)
print(n)            # 返回结果是： 10

1.2 golang

package main
import "fmt"

func bin_search(arr []int, finddata int) int {
	low := 0
	high := len(arr) - 1
	for low <= high {
		mid := (low + high) / 2
		if arr[mid] > finddata {
			high = mid - 1
		} else if arr[mid] < finddata {
			low = mid + 1
		} else {
			return mid
		}
	}
	return -1
}

func main() {
	arr := []int{1,3,4,5,6,7,8,9}
	id := bin_search(arr, 4)
	if id != -1 {
		fmt.Println(id, arr[id])    // 2 4
	} else { 
		fmt.Println("没有找到数据")
	}
}