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
-bingo_num = 20
-num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
-low = 0
-high = len(num_list)-1
-while low <= high:
-    mid = (low+high) // 2
-    guess_num = bingo_num:
-    print("找的了,他在列表里的索引是：",mid)
-    break
-    elif guess_num < bingo_num:
-        low = mid+1
-    elif guess_num > bingo_num:
-        high = mid-1
+import random
+
+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 = alist[mid]
+        if guess == num:
+            return mid
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+        elif guess < num:
+            low = mid+1
+        else:
+            high = mid - 1
+    return None
+result = binary_search(alist,num)
+print("老师给的数是：", num)
+print("它在里面的索引是：",result)
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