save project

my_search.py

@@ -6,4 +6,21 @@ for i in range(1, 101):
 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):
+    print("目标数字是"+str(num))
+    minIndex=0
+    maxIndex=len(alist)-1
+
+    while minIndex<=maxIndex:
+        mid=(minIndex+maxIndex)//2
+        if mid==num:
+            return minIndex
+        elif alist[mid]>num:
+            maxIndex=mid-1
+        else:
+            minIndex=mid+1
+    
+    return None
+print(binary_search(alist,num))
+
+    
\ No newline at end of file