05瓯信算面向对象实验

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： [email protected]

1. 实验3

  1. 拷贝5.4节中的程序：

       1    #define ALLOCSIZE 10000 /* size of available space */
   2 
   3    static char allocbuf[ALLOCSIZE]; /* storage for alloc */
   4    static char *allocp = allocbuf;  /* next free position */
   5 
   6    char *alloc(int n)    /* return pointer to n characters */
   7    {
   8        if (allocbuf + ALLOCSIZE - allocp >= n) {  /* it fits */
   9            allocp += n;
  10            return allocp - n; /* old p */
  11        } else      /* not enough room */
  12            return 0;
  13    }
  14 
  15    void afree(char *p)  /* free storage pointed to by p */
  16    {
  17        if (p >= allocbuf && p < allocbuf + ALLOCSIZE)
  18            allocp = p;
  19    }
    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

       1   /* getline:  read a line into s, return length  */
   2    int getline(char s[],int lim)
   3    {
   4        int c, i;
   5 
   6        for (i=0; i < lim-1 && (c=getchar())!=EOF && c!='\n'; ++i)
   7            s[i] = c;
   8        if (c == '\n') {
   9            s[i] = c;
  10            ++i;
  11        }
  12        s[i] = '\0';
  13        return i;
  14    }

  3. 5.6节

       1    #include <stdio.h>
   2    #include <string.h>
   3 
   4    #define MAXLINES 5000     /* max #lines to be sorted */
   5 
   6    char *lineptr[MAXLINES];  /* pointers to text lines */
   7 
   8    int readlines(char *lineptr[], int nlines);
   9    void writelines(char *lineptr[], int nlines);
  10 
  11    void qsort(char *lineptr[], int left, int right);
  12 
  13    /* sort input lines */
  14    main()
  15    {
  16        int nlines;     /* number of input lines read */
  17 
  18        if ((nlines = readlines(lineptr, MAXLINES)) >= 0) {
  19            qsort(lineptr, 0, nlines-1);
  20            writelines(lineptr, nlines);
  21            return 0;
  22        } else {
  23            printf("error: input too big to sort\n");
  24            return 1;
  25        }
  26    }
  27 
  28    #define MAXLEN 1000  /* max length of any input line */
  29    int getline(char *, int);
  30    char *alloc(int);
  31 
  32    /* readlines:  read input lines */
  33    int readlines(char *lineptr[], int maxlines)
  34    {
  35        int len, nlines;
  36        char *p, line[MAXLEN];
  37 
  38        nlines = 0;
  39        while ((len = getline(line, MAXLEN)) > 0)
  40            if (nlines >= maxlines || (p = alloc(len)) == NULL)
  41                return -1;
  42            else {
  43                line[len-1] = '\0';  /* delete newline */
  44                strcpy(p, line);
  45                lineptr[nlines++] = p;
  46            }
  47        return nlines;
  48    }
  49 
  50    /* writelines:  write output lines */
  51    void writelines(char *lineptr[], int nlines)
  52    {
  53        int i;
  54 
  55        for (i = 0; i < nlines; i++)
  56            printf("%s\n", lineptr[i]);
  57    }

    及qsort和swap

       1 void qsort(char *v[], int left, int right)
   2 {
   3     int i, last;
   4     void swap(char *v[], int i, int j);
   5 
   6     if (left >= right)  /* do nothing if array contains */
   7         return;         /* fewer than two elements */
   8     swap(v, left, (left + right)/2);
   9     last = left;
  10     for (i = left+1; i <= right; i++)
  11         if (strcmp(v[i], v[left]) < 0)
  12             swap(v, ++last, i);
  13     swap(v, left, last);
  14     qsort(v, left, last-1);
  15     qsort(v, last+1, right);
  16 }
  17 /* swap:  interchange v[i] and v[j] */
  18 void swap(char *v[], int i, int j)
  19 {
  20     char *temp;
  21 
  22     temp = v[i];
  23     v[i] = v[j];
  24     v[j] = temp;
  25 }
  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;

2. 实验6

基础知识参看：C++类与对象

3. 实验7

相关基础知识：C++继承与多态

05瓯信算面向对象实验 (2008-02-23 15:34:05由localhost编辑)