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
+a=9
+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+high=len(num_list)
+low=0
+while True:
+    mid=(high+low)//2
+    if num_list[mid]==a:
+        print("找到"+str(a)+"，索引"+str(mid))
+        break
+    elif num_list[mid]<a:
+        if high==low:
+           print("没有"+str(a))
+           break
+        else:
+            low=mid+1
+    else:
+        if high==low:
+            print("没有"+str(a))
+            break
+        else:
+            high=mid-1