auto save

my_search.py

 import random
 import random
-
-alist = []
-for i in range(1, 101):
+alist=[]
+l=0
+for i in range(1,101):
     alist.append(i)
     alist.append(i)
-num = random.choice(alist)
-# 请完善二分查找函数binary_search(),查找出num在列表alist里面的索引位置
-
+num=random.choice(alist)
 def binary_search(alist,num):
 def binary_search(alist,num):
+    low=0
+    h=len(alist)-1
+    while low<=h:
+        m=(low+h)//2
+        guess=alist[m]
+        if guess==num:
+            return m
+        elif guess<num:
+            low=m+1
+        else:
+            h=m-1
+    return None
+print(binary_search(alist,7))
+
+
+