last lab

labPython/lab17/task_1.py

@@ -0,0 +1,63 @@
+class Node:
+    def __init__(self, data):
+        self.data = data
+        self.prev = None
+        self.next = None
+
+
+def create_list(arr):
+    if not arr:
+        return None
+    head = Node(arr[0])
+    cur = head
+    for x in arr[1:]:
+        n = Node(x)
+        cur.next = n
+        n.prev = cur
+        cur = n
+    return head
+
+
+def print_list(head):
+    res = []
+    while head:
+        res.append(str(head.data))
+        head = head.next
+    print("Список:", " ".join(res) if res else "null")
+
+
+def remove_odd_positions(head):
+    index = 1
+    cur = head
+    new_head = None
+    last = None
+    while cur:
+        nxt = cur.next
+        if index % 2 == 0:
+            if not new_head:
+                new_head = cur
+                cur.prev = None
+            else:
+                last.next = cur
+                cur.prev = last
+            last = cur
+        index += 1
+        cur = nxt
+    if last:
+        last.next = None
+    return new_head
+
+
+while True:
+    try:
+        print("\n1 - Ввести список\n0 - Выход")
+        cmd = input("Выбор: ")
+        if cmd == "0":
+            break
+        if cmd == "1":
+            arr = list(map(int, input("Введите числа: ").split()))
+            head = create_list(arr)
+            head = remove_odd_positions(head)
+            print_list(head)
+    except:
+        print("Ошибка ввода")

labPython/lab17/task_2.py

@@ -0,0 +1,58 @@
+class Node:
+    def __init__(self, data):
+        self.data = data
+        self.prev = None
+        self.next = None
+
+
+def create_list(arr):
+    if not arr:
+        return None, None
+    head = Node(arr[0])
+    cur = head
+    for x in arr[1:]:
+        n = Node(x)
+        cur.next = n
+        n.prev = cur
+        cur = n
+    return head, cur
+
+
+def print_list(head):
+    res = []
+    cur = head
+    while cur:
+        res.append(str(cur.data))
+        cur = cur.next
+    print("Список:", " ".join(res))
+
+
+def shift(head, last, k):
+    if not head:
+        return head, last
+    last.next = head
+    head.prev = last
+    cur = head
+    for _ in range(k):
+        cur = cur.next
+    new_head = cur
+    new_last = cur.prev
+    new_last.next = None
+    new_head.prev = None
+    return new_head, new_last
+
+
+while True:
+    try:
+        print("\n1 - Ввести список\n0 - Выход")
+        cmd = input("Выбор: ")
+        if cmd == "0":
+            break
+        if cmd == "1":
+            arr = list(map(int, input("Введите числа: ").split()))
+            k = int(input("Введите K: "))
+            head, last = create_list(arr)
+            head, last = shift(head, last, k)
+            print_list(head)
+    except:
+        print("Ошибка")

labPython/lab17/task_3.py

@@ -0,0 +1,80 @@
+class Node:
+    def __init__(self, data):
+        self.data = data
+        self.prev = None
+        self.next = None
+
+
+class IntList:
+    def __init__(self, head):
+        self.first = head
+        self.last = head
+        self.current = head
+        while self.last and self.last.next:
+            self.last = self.last.next
+
+    def ToFirst(self):
+        self.current = self.first
+
+    def ToNext(self):
+        if self.current and self.current.next:
+            self.current = self.current.next
+
+    def SetData(self, d):
+        if self.current:
+            self.current.data = d
+
+    def IsLast(self):
+        return self.current == self.last
+
+    def process(self):
+        self.ToFirst()
+        index = 1
+        count = 0
+        while self.current:
+            count += 1
+            if index % 2 == 1:
+                self.SetData(0)
+            if self.IsLast():
+                break
+            self.ToNext()
+            index += 1
+        return count
+
+    def print_list(self):
+        cur = self.first
+        res = []
+        while cur:
+            res.append(str(cur.data))
+            cur = cur.next
+        print("Список:", " ".join(res))
+
+
+def create(arr):
+    if not arr:
+        return None
+    head = Node(arr[0])
+    cur = head
+    for x in arr[1:]:
+        n = Node(x)
+        cur.next = n
+        n.prev = cur
+        cur = n
+    return head
+
+
+while True:
+    try:
+        print("\n1 - Ввести список\n0 - Выход")
+        cmd = input("Выбор: ")
+        if cmd == "0":
+            break
+        if cmd == "1":
+            arr = list(map(int, input("Введите числа: ").split()))
+            head = create(arr)
+            lst = IntList(head)
+            n = lst.process()
+            print("Количество:", n)
+            lst.print_list()
+    except:
+        print("Ошибка")

labPython/lab17/task_4.py

@@ -0,0 +1,65 @@
+class Node:
+    def __init__(self, data):
+        self.data = data
+        self.prev = self
+        self.next = self
+
+
+def create_barrier_list(arr):
+    barrier = Node(0)
+    last = barrier
+    for x in arr:
+        n = Node(x)
+        n.prev = last
+        n.next = barrier
+        last.next = n
+        barrier.prev = n
+        last = n
+    return barrier
+
+
+def print_list(barrier):
+    cur = barrier.next
+    res = []
+    while cur != barrier:
+        res.append(str(cur.data))
+        cur = cur.next
+    print("Список:", " ".join(res) if res else "пусто")
+
+
+def split(barrier, current):
+    new_barrier = Node(0)
+    if current == barrier:
+        return new_barrier
+    last = barrier.prev
+    new_barrier.next = current
+    new_barrier.prev = last
+    current.prev.next = barrier
+    barrier.prev = current.prev
+    current.prev = new_barrier
+    last.next = new_barrier
+    return new_barrier
+
+
+while True:
+    try:
+        print("\n1 - Ввести список\n0 - Выход")
+        cmd = input("Выбор: ")
+        if cmd == "0":
+            break
+        if cmd == "1":
+            arr = list(map(int, input("Введите числа: ").split()))
+            barrier = create_barrier_list(arr)
+            print_list(barrier)
+            idx = int(input("Индекс текущего элемента (с 1): "))
+            cur = barrier.next
+            for _ in range(idx - 1):
+                if cur != barrier:
+                    cur = cur.next
+            new_barrier = split(barrier, cur)
+            print("Первый список:")
+            print_list(barrier)
+            print("Второй список:")
+            print_list(new_barrier)
+    except:
+        print("Ошибка")