save project

my_search.py

@@ -8,4 +8,17 @@ num = random.choice(alist)
 
 def binary_search(alist,num):
     low=0
-    
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+    high=len(alist)-1
+    while low<=high:
+        mid=(low+high)//2
+        guess=alist[mid]
+        if guess==num:
+            return mid
+        elif guess<num:
+            low=mid+1
+        else:
+            high=mid-1
+    return None        
+result = binary_search(alist,num)
+print("老师给的数是:",num) 
+print("他在列表里的索引是:",result)           
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