1721:交换链表中的节点

LeetCode/src/main/java/leetcode/editor/cn/SwappingNodesInALinkedList.java

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+//给你链表的头节点 head 和一个整数 k 。 
+//
+// 交换 链表正数第 k 个节点和倒数第 k 个节点的值后，返回链表的头节点（链表 从 1 开始索引）。 
+//
+// 
+//
+// 示例 1： 
+//
+// 
+//输入：head = [1,2,3,4,5], k = 2
+//输出：[1,4,3,2,5]
+// 
+//
+// 示例 2： 
+//
+// 
+//输入：head = [7,9,6,6,7,8,3,0,9,5], k = 5
+//输出：[7,9,6,6,8,7,3,0,9,5]
+// 
+//
+// 示例 3： 
+//
+// 
+//输入：head = [1], k = 1
+//输出：[1]
+// 
+//
+// 示例 4： 
+//
+// 
+//输入：head = [1,2], k = 1
+//输出：[2,1]
+// 
+//
+// 示例 5： 
+//
+// 
+//输入：head = [1,2,3], k = 2
+//输出：[1,2,3]
+// 
+//
+// 
+//
+// 提示： 
+//
+// 
+// 链表中节点的数目是 n 
+// 1 <= k <= n <= 105 
+// 0 <= Node.val <= 100 
+// 
+// Related Topics 链表 
+// 👍 13 👎 0
+
+package leetcode.editor.cn;
+
+import com.code.leet.entiy.ListNode;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+//1721:交换链表中的节点
+public class SwappingNodesInALinkedList {
+    public static void main(String[] args) {
+        Solution solution = new SwappingNodesInALinkedList().new Solution();
+//        List<Integer> list = Arrays.asList(1, 2, 3, 4, 5);
+        List<Integer> list = Arrays.asList(7, 9, 6, 6, 7, 8, 3, 0, 9, 5);
+        solution.swapNodes(new ListNode(list), 5);
+    }
+
+//leetcode submit region begin(Prohibit modification and deletion)
+
+    /**
+     * Definition for singly-linked list.
+     * public class ListNode {
+     * int val;
+     * ListNode next;
+     * ListNode() {}
+     * ListNode(int val) { this.val = val; }
+     * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+     * }
+     */
+    class Solution {
+        public ListNode swapNodes(ListNode head, int k) {
+            List<ListNode> list = new ArrayList<>();
+            ListNode temp = head;
+            while (temp != null) {
+                list.add(temp);
+                temp = temp.next;
+            }
+            int tem = list.get(k - 1).val;
+            list.get(k - 1).val = list.get(list.size() - k).val;
+            list.get(list.size() - k).val = tem;
+            return head;
+        }
+    }
+//leetcode submit region end(Prohibit modification and deletion)
+
+}