save project

my_search.py

@@ -8,4 +8,18 @@ num = random.choice(alist)
 
 
 def binary_search(alist,num):
 def binary_search(alist,num):
     low = 0
     low = 0
-    
+    high = len(alist)-1
\ No newline at end of file
+    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)
\ No newline at end of file