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
-    a=num_list[mid]
-    if a==9:
-        print("找到了",mid)
-        break
-    elif a<bingo_num :
-        low=mid+1
-    elif a>bingo_num:
-        high=mid-1
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+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
+        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("他在",result)            
+
+   
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