save project

my_search.py

 import random
 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 = 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
 # 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 
+        num = alist[mid]  
+        if num == num:
+            return mid
+            break
+        elif num < num:
+            low = mid+1
+        elif num > num:
+            high = mid-1
+print(binary_search(alist,1))
\ No newline at end of file