利用C++单链表写一个乐库管理系统

好的，下面是一个基于单链表的乐库管理系统的C++实现方案，供您参考：

#include <iostream>
#include <string>
using namespace std;

// 定义歌曲信息结构体
struct Song {
    string name;
    string artist;
    string album;
    int duration;
};

// 定义单链表节点结构体
struct SongNode {
    Song song;
    SongNode* next;
};

// 定义乐库管理系统类
class MusicLibrary {
public:
    // 构造函数
    MusicLibrary() {
        head = NULL;
        count = 0;
    }

    // 析构函数
    ~MusicLibrary() {
        // 释放链表内存
        SongNode* p = head;
        while (p) {
            SongNode* q = p->next;
            delete p;
            p = q;
        }
    }

    // 添加歌曲
    void addSong(Song song) {
        SongNode* node = new SongNode;
        node->song = song;
        node->next = head;
        head = node;
        count++;
    }

    // 删除歌曲
    void removeSong(string name) {
        SongNode* p = head;
        SongNode* q = NULL;
        while (p) {
            if (p->song.name == name) {
                if (q) {
                    q->next = p->next;
                } else {
                    head = p->next;
                }
                delete p;
                count--;
                return;
            }
            q = p;
            p = p->next;
        }
        cout << "歌曲不存在" << endl;
    }

    // 修改歌曲信息
    void updateSong(string name, Song song) {
        SongNode* p = head;
        while (p) {
            if (p->song.name == name) {
                p->song = song;
                return;
            }
            p = p->next;
        }
        cout << "歌曲不存在" << endl;
    }

    // 按歌曲名称查找歌曲
    Song* findSong(string name) {
        SongNode* p = head;
        while (p) {
            if (p->song.name == name) {
                return &(p->song);
            }
            p = p->next;
        }
        return NULL;
    }

    // 获取歌曲数量
    int getCount() {
        return count;
    }

private:
    SongNode* head;
    int count;
};

// 测试代码
int main() {
    MusicLibrary library;

    // 添加几首歌曲
    Song song1 = {"演员", "薛之谦", "初学者", 230};
    Song song2 = {"绅士", "薛之谦", "绅士", 200};
    Song song3 = {"认真的雪", "薛之谦", "认真的雪", 260};
    library.addSong(song1);
    library.addSong(song2);
    library.addSong(song3);
    cout << "当前歌曲数量：" << library.getCount() << endl;

    // 查找歌曲
    Song* pSong = library.findSong("绅士");
    if (pSong) {
        cout << "歌曲名称：" << pSong->name << endl;
        cout << "歌手名称：" << pSong->artist << endl;
        cout << "专辑名称：" << pSong->album << endl;
        cout << "歌曲时长：" << pSong->duration << endl;
    } else {
        cout << "未找到歌曲" << endl;
    }

    // 修改歌曲信息
    Song song4 = {"绅士", "薛之谦", "绅士（Live版）", 250};
    library.updateSong("绅士", song4);
    pSong = library.findSong("绅士");
    if (pSong) {
        cout << "歌曲名称：" << pSong->name << endl;
        cout << "歌手名称：" << pSong->artist << endl;
        cout << "专辑名称：" << pSong->album << endl;
        cout << "歌曲时长：" << pSong->duration << endl;
    } else {
        cout << "未找到歌曲" << endl;
    }

    // 删除歌曲
    library.removeSong("演员");
    cout << "当前歌曲数量：" << library.getCount() << endl;

    return 0;
}

该代码定义了一个MusicLibrary类，包含了添加歌曲、删除歌曲、修改歌曲信息、按歌曲名称查找歌曲等功能。该类内部使用单链表来存储歌曲信息。在测试代码中，我们添加了三首歌曲，然后查找歌曲、修改歌曲信息、删除歌曲，并输出当前歌曲数量。