【數據結構】線性、鏈式List簡單實現

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線性數組實現

#include <stdio.h>
#include <stdlib.h>

#define ERROR 0
#define OK 1
#define OVERFLOW -1
#define TRUE 1
#define FALSE 0
#define INIT_SIZE 5

typedef int ElemType;
typedef int Status;
typedef struct List {
    ElemType *elem;
    int capacity;
    int length;
} List;

void initList(List &L) {
    L.elem = (ElemType *) malloc(sizeof(ElemType) * INIT_SIZE);
    L.length = 0;
    L.capacity = INIT_SIZE;
}

//獲取元素
ElemType getElem(List &L, int index) {
    if (index < 0 || index >= L.length) exit(ERROR);
    return L.elem[index];
}


Status extendCapacity(List &L) {
    ElemType *newElem = (ElemType *) malloc(sizeof(ElemType) * (L.capacity * 2 + 1));
    for (int i = 0; i < L.length; i++) {
        newElem[i] = L.elem[i];
    }
    L.elem = newElem;
    L.capacity = L.capacity * 2 + 1;
    return OK;
}

Status addElem(List &L, ElemType e) {
    if (L.length > L.capacity)extendCapacity(L);
    L.elem[L.length++] = e;
    return OK;
};

Status insertElem(List &L, ElemType e, int index) {
    if (index < 0 || index > L.length)return ERROR;
    if (L.length > L.capacity)extendCapacity(L);
    for (int i = L.length; i > index; i--) {
        L.elem[i] = L.elem[i - 1];
    }
    L.elem[index] = e;
    L.length++;
    return OK;
}

Status deleteElem(List &L, int index) {
    if (index < 0 || index >= L.length)return ERROR;
    for (int i = index; i < L.length - 1; i++) {
        L.elem[i] = L.elem[i + 1];//i+1<length --> i<length-1
    }
    L.length--;
    return OK;
}

void printList(List &L) {
    for (int i = 0; i < L.length; i++)
        printf("%d\n", L.elem[i]);
}

int isEmpty(List &L) {
    if (L.length == 0)return TRUE;
    return FALSE;
}

//test
int main() {
    List L;//declare
    initList(L);//初始化

    addElem(L, 1);
    addElem(L, 2);
    addElem(L, 3);
    addElem(L, 4);
    addElem(L, 5);
    addElem(L, 6);//到此元素,擴展容量(初始容量5)
    addElem(L, 7);
    insertElem(L, 0, 0);//在頭部插入0
    insertElem(L, 0, L.length);//在尾部插入0

    deleteElem(L, 0);//刪除首元素0
    printList(L);

    printf("------------\n");
    printf("%d\n", getElem(L, 3));
    return 0;
}

鏈式實現

#include <iostream>
using namespace std;
typedef int ElemType;

typedef struct LNode {
    ElemType data;
    struct LNode *next;
} LNode, *LinkList;

void createList(LinkList &L) {
    L = new LNode;//head node
    L->next = NULL;
}

//初始化並輸入n個元素
void createList(LinkList &L,int n){
    L = new LNode;
    L->next = NULL;

    //逆序 前插發
//    for(int i=0;i<n;i++){
//        LNode *new_node = new LNode;
//        cin>>new_node->data;
//        new_node->next = NULL;
//        new_node->next = L->next;
//        L->next = new_node;
//    }

    //正序 後插法
    LinkList p = L;
    for(int i=0;i<n;i++){
        LNode *new_node = new LNode;
        cin>>new_node->data;
        new_node->next = NULL;//init
        p->next = new_node;
        p = p->next;//point tail elem
    }


}


//取L中第i個元素返回
ElemType getELem(LinkList L, int i) {
    LinkList p = L;
    int j = 0;

    while (p && j < i-1) {
        p = p->next;
        j++;
    }

    if (!p || j > i-1) {
        cout << "error i>n,i<0 " << endl;
        return 0;
    }
    return p->next->data;
}

//在地i個位置插入節點
void insert(LinkList &L, int i, ElemType e) {
    LinkList p;
    p = L;
    int j = 0;
    while (p && j < i-1) {
        p = p->next;
        j++;
    }

    if (!p || j > i) {
        cout << "error i<1-1, i>n+1" << endl;
        return;
    }

    LNode *new_node = new LNode;
    new_node->data = e;
    new_node->next = NULL;

    //p是最後一個節點
    if(!p->next){
        p->next = new_node;
        return;
    }

    new_node->next = p->next;
    p->next = new_node;
}

//刪除L中第i個元素
void del(LinkList &L, int i) {
    LinkList p = L;//head element
    int j = 0;
    while (p && j < i - 1) {
        p = p->next;
        j++;
    }

    if (!(p->next) || j > i - 1) {
        cout << "i<1 , i>n";
        return;
    }
    LNode *del_node = p->next;

    //如果del_node後不存在節點
    if (!del_node->next) {
        delete (del_node);
        p->next = NULL;
        return;
    }
    //連接鏈表
    p->next = p->next->next;
    delete (del_node);
}

void printList(LinkList L){
    int i=0;
    while(L->next != NULL){
        L=L->next;
        i++;
        printf("No.%d elem:%d\n",i,L->data);
    }

}

//test
int main() {
    LinkList L;
    createList(L,3);//1 2 3
    insert(L,2,222);
    printList(L);
    del(L,2);
    cout<<"-------------"<<endl;
    printList(L);


    cout<<"-------------"<<endl;
    ElemType e = getELem(L,1);
    cout<<e<<endl;

    return 0;
}

總結

線性表使用數組實現, 特點是讀取快, 插入刪除慢;
鏈表使用一個個node節點, 使用指針關聯node之間的關係, 特點是讀取慢, 插入刪除快;