86. [链表]分隔链表

86. 分隔链表

// 执行耗时:0 ms,击败了100.00% 的Java用户
// 内存消耗:37.8 MB,击败了94.44% 的Java用户

class Solution {
    public ListNode partition(ListNode head, int x) {
        // 采用328.奇偶链表类似的思路
        // 创建两个链表后再拼接
        ListNode sentinel1 = new ListNode(0), sentinel2 = new ListNode(0);
        ListNode curr1 = sentinel1, curr2 = sentinel2;
        while (head != null){
            if (head.val < x){
                curr1.next = head;
                curr1 = curr1.next;
            } else {
                curr2.next = head;
                curr2 = curr2.next;
            }
            head = head.next;
        }
        curr1.next = sentinel2.next;
        curr2.next = null;
        return sentinel1.next;
    }
}