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]
-low = 0
-high = len(num_list)-1
-bingo_num = 9
-while True:   
-    mid = (low + high)//2
-    guess = num_list[mid]
-    if low <= high:
-        if guess == bingo_num :
-            print("找到了,它在列表的索引位置为:",mid)
-            break
-        elif guess < bingo_num:
-            low = mid + 1
-        elif guess > bingo_num:
-            high = mid - 1
-    else:
-        print("该数字不在本列表当中")
-        exit()
\ No newline at end of file
+import random
+num_list = []
+for i in range(1,101):
+    num_list.append(i)
+num = random.choice(num_list)
+
+def binary_search(num_list,num):   
+    low = 0
+    high = len(num_list)-1
+    while True:   
+        mid = (low + high)//2
+        guess = num_list[mid]
+        if low <= high:
+            if guess == num :
+                return mid
+            elif guess < num:
+                low = mid + 1
+            else :
+                high = mid - 1
+    return None
+a = binary_search(num_list,num)
+print("老师给出的数是:",num)
+print("它在列表的索引位置为:",a)
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