save project

my_search.py

-import random
-
 alist = []
 alist = []
 for i in range(1, 101):
 for i in range(1, 101):
     alist.append(i)
     alist.append(i)
-num = random.choice(alist)
+num = 55
 # 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
 # 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):
+def binary_search(alist,num):
+    low =0
\ No newline at end of file
+    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        
+c = binary_search(alist,num)
+print(c)
+        
\ No newline at end of file