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
+i=0
+j=len(num_list)-1
+guess = 20
+while i<=j:
+    mid=(i+j)//2
+    if num_list[mid]==guess:
+        print('找到了,索引下标为'+str(mid))
+        break
+    elif num_list[mid]<guess:
+        i=mid+1
+    else:
+        j=mid-1
+
+if i>j:
+    print('不存在')
+