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]
+
+def chazaho(s):
+    guess=0
+    high=len(num_list)
+    mid=0
+    aaa=s
+    while not (mid>high or num_list[guess]==aaa):
+        guess=(high+mid)//2
+        if aaa>guess:
+            mid=guess-1
+        elif aaa<guess:
+            high=guess-1
+        else:
+            pass
+    if mid>high:
+        return "找不到"
+    else:
+        return "索引是"+str(guess)
+
+print(chazaho(20))
+print(chazaho(9))
\ No newline at end of file

fu.py

+num_list = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
+bingo_num=9
+low=0
+high=len(num_list)-1
+while low<=high:
+    mid=(low+high) // 2
+    guess_num=num_list[mid]
+    if guess_num==bingo_num:
+        print("找到了，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
\ No newline at end of file

my_search.py

@@ -6,4 +6,19 @@ for i in range(1, 101):
 num = random.choice(alist)
 # 请完善二分查找函数binary_search(),查找出num在列表alist里面的索引位置
 
-def binary_search(alist,num):
\ No newline at end of file
+def binary_search(alist,num):
+    bingo_num=num
+    low=0
+    high=len(alist)-1
+    while low<=high:
+        mid=(low+high) // 2
+        guess_num=alist[mid]
+        if guess_num==bingo_num:
+            print("找到了，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
+
+binary_search(alist,num)
\ No newline at end of file