Singly linked list segment reversal

6-1 Reversal of Singly Linked List Segments (25 points)
Given a singly linked list with a leading node and an integer K, you are required to reverse every K nodes in the linked list. For example, given a singly linked list 1→2→3→4→5→6 and K=3, you need to transform the linked list into 3→2→1→6→5→4; if K=4, you should get 4→3→ 2→1→5→6. Function interface definition: void K_Reverse( List L, int K );

其中List结构定义如下：typedef struct Node *PtrToNode;

struct Node { ElementType Data; /* store node data / PtrToNode Next; / pointer to the next node / }; typedef PtrToNode List; / define singly linked list type*/

L是给定的带头结点的单链表，K是每段的长度。函数K_Reverse应将L中的结点按要求分段逆转。裁判测试程序样例：#include <stdio.h>

#include <stdlib.h>

typedef int ElementType;

typedef struct Node PtrToNode;
struct Node { ElementType Data; /
store node data /
PtrToNode Next; / pointer to the next node /
};
typedef PtrToNode List; / define singly linked list type*/

List ReadInput(); /* Referee implementation, details are not shown /
void PrintList( List L ); / Referee implementation, details are not shown*/
void K_Reverse( List L, int K );

int main()
{
List L;
int K;

L = ReadInput();
scanf("%d", &K);
K_Reverse( L, K );
PrintList( L );

return 0;

}

/* Your code will be embedded here */

输入样例：6

1 2 3 4 5 6
4

输出样例：4 3 2 1 5 6

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My code

void K_Reverse( List L, int K )
{
 List Old_head,Old2_head,New_head,Temp,H=L->Next;
 int num=0;
 
 while(H){
  num++;
  H=H->Next;
 }
 
 if(K>1&&num>=K){
  int i,j;
  Old_head=L->Next; 
  Old2_head=L->Next; /*记录表头位置*/
  Temp=Old_head->Next; /*记录未逆转的头结点的下一个结点*/ 
  New_head=L;
  for(i=0;i<num/K;i++){
   for(j=0;j<K;j++){  /*每次将New_head->Next的位置赋给Old_head->Next,然后将Old_head的值赋给New_head->Next*/ 
    Old_head->Next=New_head->Next;
    New_head->Next=Old_head;
    Old_head=Temp;  /*每次未逆转的结点向后移一位*/
    if(Temp)
     Temp=Temp->Next;
   }
   New_head=Old2_head; /*已逆转的链表接上Old2_head这个位置上，也就是L->Next这个位置上*/ 
   Old2_head=Old_head;/*重新开始需要把记录表头的位置更改为下一个分段的头结点*/ 
  }
  New_head->Next=Old_head; /*循环结束需要把已逆转的尾巴接上Old_head上，也就是剩下的未逆转的头结点上*/ 
 }
}

Singly linked list segment reversal

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