save project

my_search.py

@@ -7,4 +7,34 @@ 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
 # 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):
 def binary_search(alist,num):
-    
+    low = 0
\ No newline at end of file
+    high =len(alist)-1
+    while low <= high:
+        mid = (low+high)//2
+        guess = alist[mid]
+        if guess == num:
+            return mid
+        elif guess < num:
+            low = mid+1
+        elif guess > num:
+            high = mid-1
+    return None
+result = binary_search(alist,num)
+print("老师给的数是：",num)
+print("它在列表里的索引是：",result)
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py.py

+import random
+
+alist = []
+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):
+    low = 0
+    high =len(alist)-1
+    while low <= high:
+        mid = (low+high)//2
+        guess = alist[mid]
+        if guess == num:
+            print("找到了")
+            break
+        elif guess < num:
+            low = mid+1
+        elif guess > num:
+            high = mid-1
+    result = binary_search(alist,num)    
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