题解 | #链表内指定区间反转#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param head ListNode类 
 * @param m int整型 
 * @param n int整型 
 * @return ListNode类
 */
struct ListNode* reverseBetween(struct ListNode* head, int m, int n ) {
    if(!head || m == n) return head;
    struct ListNode* t = malloc(sizeof(struct ListNode));
    t->val = -1;
    t->next = head;
    struct ListNode* p = t;
    for(int i = 1; i < m; i++) {
        p = p->next;
    }
    struct ListNode* c = p->next;
    for(int i = 0; i < n - m; i++) {
        struct ListNode* n = c->next;
        c->next = n->next;
        n->next = p->next;
        p->next = n;
    }
    return t->next;
}