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
-n=9
-hight=len(num_list)-1
+import random
 
-while True:
-    mid=(low+hight)//2
-    guess=num_list[mid]
-    if guess == n:
-        print('9的是',mid)
-        break
-    if hight < low:
-        print('there is no 9')
-        break
-    if guess < n :
-        low = mid +1
-    else:
-        hight = mid-1
+alist=[]
+for i in range(1,101):
+    alist.append(i)
+num = random.choice(alist)
+def binary_search(alist,num):
+    low = 0
+    hight = len(alist)-1
+    while True:
+        mid=(low+hight)//2
+        guess=alist[mid]
+        if guess == num:
+            print(num,' is ',mid)
+            break
+        elif guess < num:
+            low = low+ 1
+        else:
+            hight = hight+1
+        if hight < low:
+            print('there is no ' , num)
+            break
 
-
-low=0
-n=20
-hight=len(num_list)-1
-
-while True:
-    mid=(low+hight)//2
-    guess=num_list[mid]
-    if guess == n:
-        print('20的是',mid)
-        break
-    if hight < low:
-        print('there is no 20')
-        break
-    if guess < n :
-        low = mid +1
-    else:
-        hight = mid-1
\ No newline at end of file
+binary_search(alist,num)
\ No newline at end of file