单链表的逆序输出分为两种情况,一种是只逆序输出,实际上不逆序;另一种是把链表逆序。本文就分别实例讲述一下两种方法。具体如下:
1.逆序输出
实例代码如下:
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#include<iostream> #include<stack> #include<assert.h> using namespace std; typedef struct node{ int data; node * next; }node; //尾部添加 node * add( int n, node * head){ node * t = new node; t->data = n; t->next = NULL; if (head == NULL){ head = t; } else if (head->next == NULL){ head->next = t; } else { node * p = head->next; while (p->next != NULL){ p = p->next; } p->next = t; } return head; } //顺序输出 void print(node * head){ node * p = head; while (p != NULL){ cout << p->data << " " ; p = p->next; } cout << endl; } //递归 void reversePrint(node * p){ if (p != NULL){ reversePrint(p->next); cout << p->data << " " ; } } //栈 void reversePrint2(node * head){ stack< int > s; while (head != NULL){ s.push(head->data); head = head->next; } while (!s.empty()){ cout << s.top() << " " ; s.pop(); } } int main(){ node * head = NULL; for ( int i = 1; i <= 5; i++){ head = add(i, head); } print(head); reversePrint(head); reversePrint2(head); system ( "pause" ); return 0; } |
逆序输出可以用三种方法: 递归,栈,逆序后输出。最后一种接下来讲到。
2.单链表逆序
实例代码如下:
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#include<iostream> #include<stack> #include<assert.h> using namespace std; typedef struct node{ int data; node * next; }node; node * add( int n, node * head){ node * t = new node; t->data = n; t->next = NULL; if (head == NULL){ head = t; } else if (head->next == NULL){ head->next = t; } else { node * p = head->next; while (p->next != NULL){ p = p->next; } p->next = t; } return head; } //循环 node * reverse(node * head){ if (head == NULL || head->next == NULL){ return head; } node * p1 = head; node * p2 = head->next; node * p3 = NULL; head->next = NULL; while (p2 != NULL){ p3 = p2; p2 = p2->next; p3->next = p1; p1 = p3; } head = p1; return head; } void print(node * head){ node * p = head; while (p != NULL){ cout << p->data << " " ; p = p->next; } cout << endl; } //递归 node * reverse2(node * p){ if (p == NULL || p->next == NULL){ return p; } node * newHead = reverse2(p->next); p->next->next = p; p->next = NULL; return newHead; } int main(){ node * head = NULL; for ( int i = 1; i <= 5; i++){ head = add(i, head); } print(head); head = reverse(head); print(head); head = reverse2(head); print(head); system ( "pause" ); return 0; } |
这里链表逆序用了两种方法:循环,递归。读者最容易理解的方法就是在纸上自己画一下。
希望本文所述实例对大家的数据结构与算法学习能有所帮助。