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
-num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
-bingo_num = 17
-low = 0
-high = len(num_list) - 1
+import random
 
-while low <= high:
-    mid = (low+high) // 2
-    guess_num = num_list[mid]
-    if guess_num == bingo_num:
-        print('找到了，它在列表中的索引是：',mid)
-        break
-    elif guess_num < bingo_num:
-        low = mid + 1
-    elif guess_num > bingo_num:
-        high = mid - 1
-    print(mid)
\ No newline at end of file
+alist = []
+for i in range(1,101):
+    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
+        elif guess_num < num:
+            low = mid + 1
+        elif guess_num > num:
+            high = mid - 1
+    return None
+
+result = binary_search(alist,num)
+print('老师给的数是：',num)
+print('它在列表中的索引是：',result)
\ No newline at end of file