数据结构——单链表的C++实现

\qquad单链表的创建、求长度、查找、插入和删除的C++实现。

#include<iostream>
using namespace std;//1.定义
typedef struct Node* List;
struct Node {int num;Node* next;
};
void input(int* a)
{cin >> *a;
}//2.创建链表
void CreateList(List* L, int n, void (*input)(int* a))
{List s;*L = new Node;(*L)->next = NULL;List LL = *L;LL->num = 1000;for (; n > 0; n--) {s = new Node;input(&s->num);s->next = (*L)->next;(*L)->next = s;}
}//3.链表长度
int Length(List L)
{List p = L;int j = 0;while (p){p = p->next;	j++;}return j;
}//4.按序号查找
List FindKth(int k, List Ptrl)
{List p = Ptrl;int i = 1;while (p != NULL && i < k) {p = p->next;i++;}if (i == k)return p;else return NULL;}//5.按值查找
List Find(int x, List Ptrl)
{List p = Ptrl;while (p != NULL && p->num != x) {p = p->next;}return p;
}//6.插入
List Insert(int x, int i, List Ptrl)
{List p, s;if (i == 1) {s = new Node;s->num = x;s->next = Ptrl;return s;}p = FindKth(i - 1, Ptrl);if (p == NULL) {cout << "参数i错" << endl;return NULL;}else {s = new Node;s->num = x;s->next = p->next;p->next = s;return Ptrl;}
}//7.删除
List Delete(int i, List Ptrl)
{List p, s;if (i == 1) {s = Ptrl;Ptrl = Ptrl->next;delete s;return Ptrl;}p = FindKth(i - 1, Ptrl);if (p == NULL) {cout << "第" << i - 1 << "个结点不存在" << endl;return NULL;}else if (p->next == NULL) {cout << "第" << i << "个结点不存在" << endl;return NULL;}else {s = p->next;p->next = s->next;delete s;return Ptrl;}
}int main()
{List L;int n;int len;cin >> n;CreateList(&L, n, input);cout << "--------------------------" << endl;int i;List L1 = L;for (i = 0; i < n; i++) {L1 = L1->next;cout << L1->num << endl;}cout << "--------------------------" << endl;List L2 = L;L2 = Delete(2, L2);for (i = 0; i < n-1; i++) {L2 = L2->next;cout << L2->num << endl;}return 0;
}