last lab

labPython/lab16/task_4.py

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+class Node:
+    def __init__(self, data):
+        self.data = data
+        self.next = None
+
+
+def build(arr):
+    head = None
+    for x in reversed(arr):
+        node = Node(x)
+        node.next = head
+        head = node
+    return head
+
+
+def process(head, m):
+    if not head:
+        return head
+
+    dummy = Node(0)
+    dummy.next = head
+    prev = dummy
+    cur = head
+    i = 1
+
+    while cur:
+        if i % 2 == 0:
+            node = Node(m)
+            prev.next = node
+            node.next = cur
+            prev = cur
+            cur = cur.next
+            i += 1
+        else:
+            prev = cur
+            cur = cur.next
+            i += 1
+
+    return dummy.next
+
+
+def print_list(h):
+    while h:
+        print(h.data, end=" ")
+        h = h.next
+    print()
+
+
+def print_last_ref(h):
+    if not h:
+        print("None")
+        return
+    while h.next:
+        h = h.next
+    print(h)
+
+
+while True:
+    try:
+        print("\n1 - создать список")
+        print("2 - обработать")
+        print("3 - вывести ссылку на последний элемент")
+        print("0 - выход")
+        c = input(">> ")
+
+        if c == "1":
+            head = build(list(map(int, input().split())))
+        elif c == "2":
+            m = int(input("M: "))
+            head = process(head, m)
+            print_list(head)
+        elif c == "3":
+            print_last_ref(head)
+        elif c == "0":
+            break
+    except:
+        print("Ошибка")