auto save

my_search.py

@@ -5,6 +5,19 @@ for i in range(1, 101):
     alist.append(i)
     alist.append(i)
 num = random.choice(alist)
 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
 # 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
-
 def binary_search(alist,num):
 def binary_search(alist,num):
-    
+    low=0
\ No newline at end of file
+    high=len(alist)-1
+    while low<=high:
+        mid=(low+high)//2
+        if alist[mid]==num:
+            return mid
+        elif alist[mid]<num:
+            low=mid+1
+        elif alist[mid]>num:
+            high=mid-1
+    return None
+result = binary_search(alist,num)
+print(num,result)
+            
+        
\ No newline at end of file