save project

1.py

+x=20
+num_list=[1,3,5,8,11,15,17,18,20,21]
+low=0
+high=len(num_list)-1
+while low<=high:
+    y=(low+high)//2
+    guess=num_list[y]
+    if guess==x:
+        print("找到了，它的索引是：",y)
+        break
+    elif guess<x:
+        low=y+1
+        y=(low+high)//2
+    else:
+        high=y-1
+        y=(low+high)//2