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
 */
#include <stdlib.h>
struct ListNode* reverseBetween(struct ListNode* head, int m, int n ) {
    // write code here
    int s = n-m;

    int count;
    struct ListNode label; 
    label.next = head;
    struct ListNode* pre = &label;

    for(count=1;count<m;count++){ //找头节点  
        pre = pre->next;
    }

    struct ListNode* now = pre->next;
    struct ListNode* new = NULL;   
    int i = 0;
    while(i<n-m){
        new = now->next;
        now->next = new->next;
        new->next = pre->next;
        pre->next = new;

        i++;
    }

    return label.next;
}