【链表】非递归过程以O(N)反转单链表

#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>

#include <stdlib.h>

struct Node;

typedef Node *PtrToNode;

typedef PtrToNode List;

typedef PtrToNode Position;

struct Node

{

int val;

Position Next;

};

void Insert(int val, List list, Position pos)

{

Node *p;

p = (Node *)malloc(sizeof(Node));

p->val = val;

p->Next=NULL;

pos->Next = p;

}

//数据结构与算法分析 习题3.12

List ReverseList(List L) {

Position CurrentPos, NextPos, PreviousPos;

PreviousPos = NULL;

CurrentPos = L; NextPos = L->Next;

while (NextPos != NULL) {

CurrentPos->Next = PreviousPos;

PreviousPos = CurrentPos;

CurrentPos = NextPos;

NextPos = NextPos->Next;

}

CurrentPos->Next = PreviousPos;

return CurrentPos;

}

void main()

{

List list, p;

Position pos,l;

p = (Node *)malloc(sizeof(Node));

pos = p;

for (int i = 1; i <= 10; i++) {

Insert(i, p, pos);

pos = pos->Next;

}

l = p->Next;

while (l) {

printf("%d ", l->val);

l = l->Next;

}

printf("\n");

list = p->Next;

list = ReverseList(list);

l = list;

while (l) {

printf("%d ", l->val);

l = l->Next;

}

getchar();

}