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
-num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
\ No newline at end of file
+
+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+b=int(input())
+low=0
+high=len(num_list)-1
+
+while True:
+    mid=(low+high)//2
+    n=num_list[mid]
+    if n==b:
+        print('找到了',mid)
+        break
+    elif n<b:
+        low=mid+1
+    elif high>low:
+        print('没有')
+        break
+    else:
+        high=mid-1
+
+