save project

my_search.py

@@ -7,18 +7,16 @@ 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):
-    bingo_num=20
-num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
-low=0
-high=len(num_list)-1
-mid=(low+high)//2
-guess_num=num_list[mid]
-if guess_num==bingo_num:
-    print("找到了，它在列表里的索引是：",mid)
-    break
-elif guess_num<bingo_num:
-    low=mid+1
-elif guess_num>bingo_num:
-    high=mid-1    
-
-    
+    low=0
+    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
+