save project

my_tree.py

-import turtle
-import random
-
-pen = turtle.Turtle()
-pen.color('sienna')      #画笔颜色
-# 画布大小
-w = turtle.Screen()
-w.bgcolor('wheat')      # wheat小麦画布颜色
-
-# 移动到起点
-def tree(n):
-    if n>=0:
-        if n<=12:
-            color_list=['snow','lightcoral']
-            color=random.choice(color_list)
-            pen.color('siema')
-            pen.pensize(n/3)
+num_list=[1,3,5,8,11,15,17,18,20,21]
+num=20
+low=0
+high=len(num_list)-1
+while low<=high:
+    mid=(low+high)//2
+    guss=num_list[mid]
+    if guss==num:
+        print("找到了")
+    elif:guss<num:
+        low=mid+1
     else:
     else:
-            pen.color('sienna')
-            pen.pensize(n/10)
-        pen.forward(n)
-        al = random.random()
-        pen.right(30*al)
-        le =15*random.random()
-        tree(n-le)
-        pen.left(60*al)
-        tree(n-le)
-        pen.right(30*al)
-        pen.up()
-        pen.backward(n)
-        pen.down()
-pen.left(90)
-pen.up()
-pen.backward(150)    # 后退
-pen.down()
-tree(50)
+        high=mid-1
+
 
 
-turtle.done()