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]
+num=20
 low=0
-high=len(num(list)-1)
+high=len(num_list)-1
 mid=(low+high)//2
-while True:    
-    if 20 in num_list[:mid]:
-        num_list.
-        high=mid
-    else:
-        num_list.pop(mid:)
-        low=mid
-    if high==low and low==mid:
-        print("找到了")
-        print(low)
-        break
-    
-    
-
+guess=num_list[mid]
+while low<=high: 
+    mid=(low+high)//2
+    guess=num_list[mid]
+    if guess==num:
+        print("找到了",str(mid))
+        break 
+    elif guess>num:
+        high=mid-1
+    elif guess<num:
+        low=mid+1
+if low>high:
+    print("没有")