save project

my_search.py

@@ -7,3 +7,17 @@ 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
 
 def binary_search(alist,num):
+    low=0
+    high=len(alist)-1
+    while high>=low:
+        mid=(high+low)//2
+        if num==alist[mid]:
+            return mid
+        elif num>alist[mid]:
+            low=mid+1
+        else:
+            high=mid-1
+    return None
+
+a=binary_search(alist,num)
+print(a)
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