save project

binary_search.py

 # 使用二分查找法，找出20在列表里面的索引
 # 使用二分查找法，找出20在列表里面的索引
-num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
-bingo_list = 20
-low=0
-high=len(num_list)-1
-while low<= high:
-    mid=(low+high)//2
-    guess_num=num_list[mid]
-    if guess_num==bingo_list :
-        print("找到了，他在列表的索引是：",mid)
-        break
-    elif guess_num<bingo_list:
-        low=mid+1
-    elif guess_num>bingo_list:
-        low=mid-1
-    
+import random
+alist=[]
+for i in range(1,100):
+    alist.append(i)
+num = random.choice(alist)
+
+
+def binary_search(alist,num):
+    low=0
+    high=len(alist)-1
+    while low<= high:
+        mid=(low+high)//2
+        guess_num=alist[mid]
+        if guess_num==num:
+            return mid
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+        elif guess_num<num:
+            low=mid+1
+        else:
+            low=mid-1
+    return None
+result = binary_search(alist,num)
+print("老师给的数是：",num)
+print("他在列表的索引是：",result)
+        
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