auto save

1.py

+import turtle
+screen=turtle.Screen()
+screen.bgcolor('black')
+pen=turtle.Pen()
+pen.speed(9)#设置画笔的速度，范围0-10，0最快，10较快，1最慢，6中等速度
+color=['red','yellow','blue','purple']
+for i in range(1,301):
+    pen.pencolor(color[i%4])
+    pen.forward(i)
+    pen.right(91)
+turtle.done()

my_search.py

@@ -4,6 +4,21 @@ alist = []
 for i in range(1, 101):
     alist.append(i)
 num = random.choice(alist)
+print(num)
 # 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):
+    low=0
+    high=len(alist)-1
+    while low<=high:
+        mid=(low+high)//2
+        m=alist[mid]
+        if num==m:
+            return mid
+        elif m<num:
+            low=mid+1
+        elif m>num:
+            high=mid-1
+    return None
+print(binary_search(alist,num))
+        
\ No newline at end of file