save project

my_search.py

@@ -4,6 +4,23 @@ alist = []
 for i in range(1, 101):
     alist.append(i)
 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 = 1
+    high = len(alist) - 1
+    while low<=high:
+        mid = (low + high)//2
+        g = alist[mid]
+        if g == num:
+            print('找到了，它的索引是：',mid)
+            return mid
+        elif g < num:
+            low = mid + 1
+        elif g > num:
+            high = mid - 1
+        if low > high:
+            return None
+a = binary_search(alist,223) 
+print(a)