用B树做的图书管理系统

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<conio.h>#include<time.h>#define N 10000#define TRUE 1#define FALSE 0#define OK 1#define ERROR 0#define INFEASIBLE -1#define OVERFLOW -2typedef int Status;typedef char *string ;#define m 3 //B-树的阶//书的结构体struct Book{unsigned int key;char bname[20];char writter[20];unsigned int left;unsigned int total;}b[N];//B- 树的存储结构typedef Book KeyType;typedef struct BTNode{int keynum;struct BTNode *parent;KeyType key[m + 1];struct BTNode *ptr[m + 1]; }BTNode,*BTree;//查找结果的存储结构体typedef struct{BTNode *pt;int i;int tag;}Result;BTree root = NULL;void InBookMess(KeyType &book);void InBookKey(KeyType &book);void ShowBookMess(Book book);void ShowBTNode(BTree p);void display(BTree T);void KeyTypeCopy(KeyType &bak,KeyType k);int Search(BTree p, KeyType K);Result SearchBTree(BTree T, KeyType K);void Insert(BTree &q, int i, KeyType x, BTree ap);void split(BTree &q, int s, BTree &ap);void NewRoot(BTree &T, BTree p, KeyType x, BTree ap);Status InsertBTree(BTree &T, KeyType K);Status BorrowBook(BTree T,KeyType k);Status ReturnBook(BTree T,KeyType k);void save(BTree p);/*************************************************/void save(BTree p)//保存文件{FILE *fp;if ((fp=fopen("book.txt","wb"))==NULL ){printf("创建文件失败!\n\n");getchar();return;}for(int i = 1; i <= p->keynum; i++){fprintf(fp,"%d %s %s %d %d\n",p->key[i].key,p->key[i].bname,p->key[i].writter,p->key[i].left,p->key[i].total);}fclose(fp);}//读取文件void read(){FILE *fp,fp1;if ((fp=fopen("book.txt","rb"))==NULL && (fp=fopen("user.txt","rb"))==NULL){printf("读取文件失败!\n\n");getchar();return;}for(int i=1;;i++){if(fscanf(fp,"%d%s%s%d%d",&b[i].key,&b[i].bname,&b[i].writter,&b[i].left,&b[i].total)= =EOF){ break; }InsertBTree(root,b[i]);}fclose(fp);}//复制结点,将某个结点的值复制到另外一个值上void KeyTypeCopy(KeyType &bak,KeyType k){bak.key = k.key;strcpy(bak.bname,k.bname);bak.left = k.left;bak.total = k.total;strcpy(bak.writter,k.writter);}//在一个结点中查找元素,返回结点的位置int Search(BTree p, KeyType K) {if(!p)return -1;int i=0;for(i = 0; i < p->keynum && p->key[i+1].key <= K.key; i++);return i;}// 在m阶B树T上查找关键字K，返回结果(pt,i,tag)Result SearchBTree(BTree T, KeyType K){BTree p, q;int found, i;Result R;p = T;q = NULL;found = FALSE;i = 0;while (p && !found) {i = Search(p, K);if (i > 0 && p->key[i].key == K.key)found = TRUE;else {q = p;p = p->ptr[i];}}if (found) {R.pt = p;R.i = i;R.tag = 1;}else {R.pt = q;R.i = i;R.tag = 0;}return R;}//插入一条记录void Insert(BTree &q, int i, KeyType x, BTree ap) { int n = q->keynum;for (int j = n; j > i; j--) {KeyTypeCopy(q->key[j + 1],q->key[j]);q->ptr[j + 1] = q->ptr[j];}KeyTypeCopy(q->key[i + 1],x);q->ptr[i + 1] = ap;if (ap)ap->parent = q;q->keynum++;}//分离结点void split(BTree &q, int s, BTree &ap) {int i,j,n = q->keynum;ap = (BTree)malloc(sizeof(BTNode));ap->ptr[0] = q->ptr[s];for (i = s + 1,j = 1; i <= n; i++,j++) {KeyTypeCopy(ap->key[j],q->key[i]);ap->ptr[j] = q->ptr[i];}ap->keynum = n - s;ap->parent = q->parent;for (i = 0; i <= n - s; i++)if (ap->ptr[i])ap->ptr[i]->parent = ap;q->keynum = s-1;}//生成一个新的树结点void NewRoot(BTree &T, BTree p, KeyType x, BTree ap) { T = (BTree)malloc(sizeof(BTNode));T->keynum = 1; //设置当前结点的元素个数T->ptr[0] = p; //设置左边结点的树根T->ptr[1] = ap; //设置右边的树根KeyTypeCopy(T->key[1],x); //将x 元素的结点值复制到T 的第一个元素中if (p) //当孩子不空的时候就设置当前结点为孩子的双亲p->parent= T;if (ap)ap->parent = T;T->parent = NULL; //当前结点的双亲为空}void ShowBTNode(BTree p) {for(int i = 1; i <= p->keynum; i++){printf("\t");printf("书号为:%d ", p->key[i].key);printf("书名为:%5s ", p->key[i].bname);printf("作者为:%5s ", p->key[i].writter);printf("剩余量为:%5d ", p->key[i].left);printf("总量为:%5d", p->key[i].total);printf("\n");}}Status InsertBTree(BTree &T, KeyType K) {//在m阶B树T上结点*q的key[i]与key[i+1]之间插入关键字K。

BTree ap;Result rs;BTree q;int i;char addnum;int finished, needNewRoot, s;KeyType x;if (!T){NewRoot(T, NULL, K, NULL);}else {rs = SearchBTree(T,K);//查找元素k 在树中的位置q = rs.pt;i = rs.i;if(rs.tag == 1){if(strcmp(q->key[i].bname,K.bname) != 0){printf("\n\t录入失败，原因:\n");printf(".\t书号冲突，请重新为该书编号!\n\n");printf("\t已经存在书号为%d 的书为:\n",q->key[i].key);ShowBookMess(q->key[i]);return FALSE;}else{printf("\n\t该书已经存在!\n\n");printf("\t是否增加其总量(y/n):");scanf("%s",&addnum);if(addnum == 'Y' || addnum == 'y'){q->key[i].total += K.total;q->key[i].left += K.left;printf("\n\t增加总量后该书的信息如下\n");}else{printf("\n\t该书的信息如下:\n");}ShowBookMess(q->key[i]);return FALSE;}}x = K;ap = NULL;finished = needNewRoot = FALSE;while (!needNewRoot && !finished) {Insert(q, i, x, ap); //插入结点if (q->keynum < m)finished = TRUE; // 插入完成else { // 分裂结点*qs = (m+1)/2;split(q, s, ap);x = q->key[s];if (q->parent) { // 在双亲结点*q中查找x的插入位置q = q->parent;i = Search(q, x);}elseneedNewRoot = TRUE;}}if (needNewRoot)NewRoot(T, q, x, ap); // 生成新根结点*T,q和ap为子树指针 }return OK;}//输入书的具体信息void InBookMess(KeyType &book){char s[5];printf("\t请输入书号:");scanf("%s",s);book.key = atoi(s);printf("\t请输入书名:");scanf("%s",&book.bname);printf("\t请输入作者:");scanf("%s",&book.writter);printf("\t请输入总量:");scanf("%s",s);book.total = atoi(s);book.left = book.total;}//输入书的关键字void InBookKey(KeyType &book){char s[5];printf("\t请输入书号:");scanf("%s",s);book.key = atoi(s);}//显示书的具体信息void ShowBookMess(Book book){printf("\t书号为:%3d\n", book.key);printf("\t书名为:%3s\n", book.bname);printf("\t作者为:%3s\n", book.writter);printf("\t剩余量为:%3d\n", book.left);printf("\t总量为:%3d\n", book.total);printf("\n");}//显示整棵树的信息void display(BTree T){int i = 0;if(T) {ShowBTNode(T); //显示这个结点的全部值for(i=0; i<=T->keynum; i++){ //使用递归的方法显示每个结点if(T->ptr[i]){display(T->ptr[i]);}}}}//借阅Status BorrowBook(BTree T,KeyType k){Result rs = SearchBTree(T,k);if(rs.tag == 0){printf("\t很抱歉!你要借阅的书不存在!\n");return FALSE;}if(rs.pt->key[rs.i].left < 1){printf("\t很抱歉!你要借阅的书已经借完!\n");return FALSE;}rs.pt->key[rs.i].left--;return OK;}//还书Status ReturnBook(BTree T,KeyType k){int number;Result rs = SearchBTree(T,k);if(rs.tag == 0){printf("\t很抱歉!不存在你要还的书!\n");return FALSE;}if(rs.pt->key[rs.i].left>=rs.pt->key[rs.i].total){printf("\t该书无借出\n");return FALSE;}else{rs.pt->key[rs.i].left++;}}//显示书的信息void ShowWriterBook(BTree p,char writer[]) { for(int i = 1; i <= p->keynum; i++){if(strcmp(p->key[i].writter,writer) == 0){printf("\t\t\t书号为:%d ", p->key[i].key);printf("书名为:%s ",p->key[i].bname);printf("作者为:%3s\n", p->key[i].writter);}}}//菜单char menu_selete(){char ch;system("cls");printf("\t************************ 图书管理系统**********************\n\n"); printf("\t1.新书入库. \t2.查找书籍. \n");printf("\t3.显示库存. \t4.借阅. \n");printf("\t5.还书 \t6.退出. \n");printf("\t*************************************************************\n\n");printf("\t请选择你所需要的操作(1~6):");do{ch = getch();}while(ch < '1' || ch > '7');return ch;}void main(){KeyType k;Result rs;read();while(1){switch(menu_selete()){case'1':system("cls");printf("\t------------------ 录入书信息----------------\n");InBookMess(k);InsertBTree(root,k);printf("\t--------- 录入结束---------\n");save(root);printf("\t当前书库的库存信息如下：\n");display(root);printf("\t按任意键返回");getch();break;case'2':system("cls");printf("\t------------------ 查找书信息----------------\n");InBookKey(k);printf("\n");rs = SearchBTree(root,k);if(rs.tag == 1){ShowBookMess(rs.pt->key[rs.i]);}else{printf("\t你要查找的书号%d 不存在!\n\n",k.key);}printf("\n\t------------------ 查找结束----------------\n");printf("\t按任意键返回");getch();。