05瓯信算面向对象实验

返回“面向对象程序设计课程”

05瓯信算面向对象实验

先打开实验报告模板，查看需要完成哪些题目，然后打开判题系统地址，在判题系统上做对相应题目，最后将正确的程序复制到实验报告中，发到邮箱。

判题系统地址：http://wzuacm.3322.org/

完成如下实验报告：

在实验报告文件名后添加你的学号姓名，比如“面向对象实验1-0530215288-张三.doc”，然后email到： czk.cpp@gmail.com

实验3

  1. 拷贝5.4节中的程序：

       #define ALLOCSIZE 10000 /* size of available space */

   static char allocbuf[ALLOCSIZE]; /* storage for alloc */
   static char *allocp = allocbuf;  /* next free position */

   char *alloc(int n)    /* return pointer to n characters */
   {
       if (allocbuf + ALLOCSIZE - allocp >= n) {  /* it fits */
           allocp += n;
           return allocp - n; /* old p */
       } else      /* not enough room */
           return 0;
   }

   void afree(char *p)  /* free storage pointed to by p */
   {
       if (p >= allocbuf && p < allocbuf + ALLOCSIZE)
           allocp = p;
   }

    或者可以将后面出现的alloc函数调用改成malloc函数调用

  2. 1.9节getline

      /* getline:  read a line into s, return length  */
   int getline(char s[],int lim)
   {
       int c, i;

       for (i=0; i < lim-1 && (c=getchar())!=EOF && c!='\n'; ++i)
           s[i] = c;
       if (c == '\n') {
           s[i] = c;
           ++i;
       }
       s[i] = '\0';
       return i;
   }

  3. 5.6节

       #include <stdio.h>
   #include <string.h>

   #define MAXLINES 5000     /* max #lines to be sorted */

   char *lineptr[MAXLINES];  /* pointers to text lines */

   int readlines(char *lineptr[], int nlines);
   void writelines(char *lineptr[], int nlines);

   void qsort(char *lineptr[], int left, int right);

   /* sort input lines */
   main()
   {
       int nlines;     /* number of input lines read */

       if ((nlines = readlines(lineptr, MAXLINES)) >= 0) {
           qsort(lineptr, 0, nlines-1);
           writelines(lineptr, nlines);
           return 0;
       } else {
           printf("error: input too big to sort\n");
           return 1;
       }
   }

   #define MAXLEN 1000  /* max length of any input line */
   int getline(char *, int);
   char *alloc(int);

   /* readlines:  read input lines */
   int readlines(char *lineptr[], int maxlines)
   {
       int len, nlines;
       char *p, line[MAXLEN];

       nlines = 0;
       while ((len = getline(line, MAXLEN)) > 0)
           if (nlines >= maxlines || (p = alloc(len)) == NULL)
               return -1;
           else {
               line[len-1] = '\0';  /* delete newline */
               strcpy(p, line);
               lineptr[nlines++] = p;
           }
       return nlines;
   }

   /* writelines:  write output lines */
   void writelines(char *lineptr[], int nlines)
   {
       int i;

       for (i = 0; i < nlines; i++)
           printf("%s\n", lineptr[i]);
   }

    及qsort和swap

    void qsort(char *v[], int left, int right)
{
    int i, last;
    void swap(char *v[], int i, int j);

    if (left >= right)  /* do nothing if array contains */
        return;         /* fewer than two elements */
    swap(v, left, (left + right)/2);
    last = left;
    for (i = left+1; i <= right; i++)
        if (strcmp(v[i], v[left]) < 0)
            swap(v, ++last, i);
    swap(v, left, last);
    qsort(v, left, last-1);
    qsort(v, last+1, right);
}
/* swap:  interchange v[i] and v[j] */
void swap(char *v[], int i, int j)
{
    char *temp;

    temp = v[i];
    v[i] = v[j];
    v[j] = temp;
}

  4. 所有的qsort换一个名字，比如qsort2

  5. 修改readlines函数

        while(scanf("%s", line)!=EOF) {
        len = strlen(line)+1;

实验6

基础知识参看：C++类与对象

实验7

相关基础知识：C++继承与多态