C语言 | Leetcode C语言题解之第147题对链表进行插入排序

题目：

题解：

struct ListNode *insertionSortList(struct ListNode *head) {
    if (head == NULL) {
        return head;
    }
    struct ListNode *dummyHead = malloc(sizeof(struct ListNode));
    dummyHead->val = 0;
    dummyHead->next = head;
    struct ListNode *lastSorted = head;
    struct ListNode *curr = head->next;
    while (curr != NULL) {
        if (lastSorted->val <= curr->val) {
            lastSorted = lastSorted->next;
        } else {
            struct ListNode *prev = dummyHead;
            while (prev->next->val <= curr->val) {
                prev = prev->next;
            }
            lastSorted->next = curr->next;
            curr->next = prev->next;
            prev->next = curr;
        }
        curr = lastSorted->next;
    }
    return dummyHead->next;
}