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,high=0,len(num_list)-1
-while True:
-    num=int(input("输入："))
-    if high>=low:
-        while True:
-            mid=(high+low)//2
-            gusses=num_list[mid]
-            if gusses==num:
-                print("索引为",mid)
+import random
+alist=[]
+for i in range(1,101):
+    alist.append(i)
+num=random.randint(1,101)
+def binary_search(list,sum):
+    low,high=0,len(list)-1
+    number=sum
+    while high>=low:
+        mid=(high+low)//2
+        gusses=list[mid]
+        if gusses==number:
+            return mid
+        elif gusses<number:
+            low=mid+1
+            if high<low:
                 break
-            elif gusses<num:
-                low=mid+1
-                if high<low:
-                    print("此数不存在")
-                    break
-            else:
-                high=mid-1
-                if high<low:
-                    print("此数不存在")
-                    break
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+        else:
+            high=mid-1
+            if high<low:
+                break
+a=binary_search(alist,num)
+print(num,a)
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