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]
+# 使用二分查找法，找出9和20在列表里面的索引 
+#num=20
\ No newline at end of file
+#low=0
+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+#high=len(num_list)-1
+def a(num,list):
+    low=0
+    high=len(num_list)-1
+    while low <= high:
+        mid=(low+high)//2
+        guess=list[mid]
+        if guess==num:
+            return mid
+        elif guess<num:
+            low=mid+1
+        else:
+            high=mid-1
+    return None                
+a=a(21,num_list)  
+print(a)        
\ No newline at end of file