算法图解-二分法

算法图解用Python来实现

1. def binary_search(list,item):
       low = 0 #用于跟踪其要在列表中查找到部分
       high = len(list)-1
       guess = list[mid]
       while low <= high:
           mid = (low+high)//2 #取整
           if guess == item: #找到了元素
               return mid
           if guess > item: #猜的数值大了
               high = mid-1
           else:                  #猜的数值小了
               low = mid+1
       return None #没有指定元素
   
   if __name__== '__main__':
       my_list = [1,3,5,7,9,11，13,15]
       print(binary_search(my_list,5))
       print(binary_search(my_list,-1))