save project

my_search.py

@@ -5,5 +5,18 @@ for i in range(1, 101):
     alist.append(i)
 num = random.choice(alist)
 # 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):
+    length=len(alist)
+    low=0;high=length-1;mid=(low+high)//2
+    while(1):
+        if num == alist[mid]:
+            return mid;
+        elif low>high:
+            return None;
+        if alist[mid] < num:
+            low=mid+1;
+        else:
+            high=mid-1;
+        mid=(low+high)//2
+print(num)
+print(binary_search(alist,num))
\ No newline at end of file