save project

binary_search.py

 # 使用二分查找法，找出9和20在列表里面的索引
 # 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]
+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
\ No newline at end of file
+def erfen(list1,num):
+    high = len(list1)-1
+    low = 0
+    while True:
+        mid = (low+high)//2
+        # print(mid)
+        guess = list1[mid]
+        if guess == num:
+            return mid
+        elif guess < num:
+            low = mid + 1
+        else:
+            high = mid - 1
+        if high < low:
+            return False
+
+print(erfen(num_list,9))
+print(erfen(num_list,20))
\ No newline at end of file