save project

1.py

+# 使用二分查找法，找出9和20在列表里面的索引
+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+low = 0
+num = 20
+high = len(num_list) - 1
+while low <= high:
+    mid = (low + high) // 2
+    guess_num = num_list[mid]
+    if guess_num == num:
+        print(mid)
+        break
+    elif num > guess_num:
+        low = mid + 1
+    else:
+        high = mid - 1

my_search.py

@@ -6,4 +6,15 @@ for i in range(1, 101):
 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):
\ No newline at end of file
+def binary_search(alist,num):
+    while low <= high:
+        mid = (low + high) // 2
+        guess = alist
+        if guess_num == num:
+            print(mid)
+            break
+        elif num > guess:
+            low = mid + 1
+        else:
+            high = mid - 1
+        return None
\ No newline at end of file