save project

my_search.py

@@ -6,4 +6,17 @@ 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):
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+def binary_search(alist,num):
+    low = 0
+    high = len(alist)-1
+    mid = (low + high)//2
+    guess = alist[mid]
+    if guess == alist[num]:
+        return num
+    elif guess < num:
+        low = mid + 1
+    else:
+        high = mid - 1
+    if low > hght:
+        return
+print(num-1)
\ No newline at end of file