save project

my_search.py

@@ -3,7 +3,23 @@ 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)
-# 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
+n = random.choice(alist)
 
 
-def binary_search(alist,num):
+
\ No newline at end of file
+def bs(alist,n):
+    l = 0
+    h = len(alist)-1
+    while l <= h:
+        m = (l + h) // 2
+        g = alist[m]
+        if g == n:
+           return m
+        elif g < n:
+            l = m + 1
+        elif g>n:
+            h = m - 1
+    return None
+r=bs(alist,n)
+print("老师给的数是",n)
+print("索引值是",r)
+            
\ No newline at end of file