save project

my_search.py

 import random
 
-alist = []
+num_lest = []
 for i in range(1, 101):
-    alist.append(i)
-num = random.choice(alist)
+    num_lest.append(i)
+num = random.choice(num_lest)
+# 使用二分查找法，找出9和20在列表里面的索引
+
+
 # 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):
\ No newline at end of file
+def binary_search(alist,num):
+    low = 0
+    high = len(alist)
+    while True:
+        if not high<low:
+            mid = (low + high)//2
+            x = alist[mid]
+            if x == num:
+                return str(num) + '在num_list中的索引是'+str(mid)
+            elif x > num:
+                high = mid-1
+            else:
+                low = mid+1
+        else:
+            return str(num) + '不在num_list中'
+a = int(input('number'))
+print(binary_search(num_lest,a))
+
+