save project

binary_search.py

 # 使用二分查找法，找出9和20在列表里面的索引
 # 使用二分查找法，找出9和20在列表里面的索引
-num = 20
-num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
-low = 0
-high = len(num_list)-1
-while low <= high:
+import random
+alist = []
+for i in range(1,101):
+    alise.append(i)
+num = random.choice(alise)
+def binary_search(alist,num):
+    low = 0
+    high = len(alist)-1
+    while low <= high:
         mid = (low+high) // 2
         mid = (low+high) // 2
         guess = num_list[mid]
         guess = num_list[mid]
         if guess == num:
         if guess == num:
-        print("找到了")
-        break
+            return mid
         elif guess < num:
         elif guess < num:
             low = mid+1
             low = mid+1
         else:
         else:
             high = mid-1
             high = mid-1
+    return None
+result = binary_search(alist,num)
+print("") 
+print("") 
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