selsolutionsc5.txt

primer c 5th edition 一书详细叙述了c语言的概念和知识。包括17章内容

   return 0;
} 

PE 11-13

/* Programming Exercise 11-13 */
#include <stdio.h>
#include <stdlib.h>        /* for atof()           */
#include <math.h>        /* for pow()            */
/* #include <console.h> */   /* Macintosh adjustment */
int main(int argc, char *argv[])
{
    double num, exp;
    
    /* argc = ccommand(&argv); */  /* Macintosh adjustment */  
    if (argc != 3)
        printf("Usage: %s number exponent\n", argv[0]);
    else
    {
        num = atof(argv[1]);
        exp = atof(argv[2]);
        printf("%f to the %f power = %g\n", num, exp, pow(num,exp));
    }
    
    return 0;
}

PE 11-15

/* Programming Exercise 11-15 */
#include <stdio.h>
#include <ctype.h>
/* #include <console.h> */   /* Macintosh adjustment */

int main(int argc, char *argv[])
{
    char mode = 'p';
    int ok = 1;
    int ch;
    
    /*argc = ccommand(&argv); */  /* Macintosh adjustment */  

    if (argc > 2)
    {
        printf("Usage: %s [-p | -u | -l]\n", argv[0]);
        ok = 0;                /* skip processing input */
    }
    else if (argc == 2)
    {
        if (argv[1][0] != '-')
        {
            printf("Usage: %s [-p | -u | -l]\n", argv[0]);
            ok = 0;
        }
        else 
            switch(argv[1][1])
            {
                case 'p' :
                case 'u' :
                case 'l' : mode = argv[1][1];
                           break;
                default  : printf("%s is an invalid flag; ", argv[1]);
                           printf("using default flag (-p).\n");
            }
    }
    
    if (ok)
        while ((ch = getchar() ) != EOF)
        {
            switch(mode)
            {
                case 'p'  :  putchar(ch);
                             break;
                case 'u'  :  putchar(toupper(ch));
                             break;
                case 'l'  :  putchar(tolower(ch));
            }
        }
                            
    return 0;
}

Chapter 12

PE 12-1

/* pe12-1.c  -- deglobalizing global.c */
/* Programming Exercise 12-1           */
/* one of several approaches */
#include <stdio.h>
void critic(int * u);
int main(void)
{
   int units;   /* units now local */

   printf("How many pounds to a firkin of butter?\n");
   scanf("%d", &units);
   while ( units != 56)
       critic(&units);
   printf("You must have looked it up!\n");
   return 0;
}

void critic(int * u)
{
   printf("No luck, chummy. Try again.\n");
   scanf("%d", u);
}

// or use a return value:
// units = critic(); 

// and have critic look like this:
/*
int critic(void)
{
   int u;
   printf("No luck, chummy. Try again.\n");
   scanf("%d", &u);
   return u;
}
*/

// or have main() collect the next value for units

PE 12-3

//pe12-3a.h

#define METRIC 0
#define US 1
#define USE_RECENT 2

void check_mode(int *pm);

void get_info(int mode, double * pd, double * pf);

void show_info(int mode, double distance, double fuel);

// pe12-3a.c
#include <stdio.h>
#include "pe12-3a.h"

void check_mode(int *pm)
{
    if (*pm != METRIC && *pm != US)
    {
        printf("Invalid mode specified. Mode %d\n", *pm);
        printf("Previous mode will be used.\n");
        *pm = USE_RECENT;
    }
}

void get_info(int mode, double * pd, double * pf)
{
    if (mode == METRIC)
        printf("Enter distance traveled in kilometers: ");
    else
        printf("Enter distance traveled in miles: ");
    scanf("%lf",pd);
    if (mode == METRIC)
        printf("Enter fuel consumed in liters: ");
    else
        printf("Enter fuel consumed  in gallons: ");
    scanf("%lf", pf);
}

void show_info(int mode, double distance, double fuel)
{
    printf("Fuel consumption is ");
    if (mode == METRIC)
        printf("%.2f liters per 100 km.\n", 100 * fuel / distance);
    else
        printf("%.1f miles per gallon.\n", distance / fuel);
}

// pe12-3.c
#include <stdio.h>
#include "pe12-3a.h"
int main(void)
{
  int mode;
  int prev_mode = METRIC;
  double distance, fuel;
  
  printf("Enter 0 for metric mode, 1 for US mode: ");
  scanf("%d", &mode);
  while (mode >= 0)
  {
        check_mode(&mode);
        if (mode == USE_RECENT)
            mode = prev_mode;
        prev_mode = mode;
      get_info(mode, &distance, &fuel);
      show_info(mode, distance, fuel);
        printf("Enter 0 for metric mode, 1 for US mode");
        printf(" (-1 to quit): ");
      scanf("%d", &mode);
  
  }
  printf("Done.\n");
  
  return 0;
}

PE 12-5

/* pe12-5.c  */
#include <stdio.h>
#include <stdlib.h>
void print(const int array[], int limit);
void sort(int array[], int limit);

#define SIZE 100
int main(void)
{
    int i;
    int arr[SIZE];
    
    for (i = 0; i < SIZE; i++)
        arr[i] = rand() % 10 + 1;
    puts("initial array");
    print(arr,SIZE);
    sort(arr,SIZE);
    puts("\nsorted array");
    print(arr,SIZE);
    
    return 0;
}

/* sort.c -- sorts an integer array in decreasing order */
void sort(int array[], int limit)
{
   int top, search, temp;

   for (top = 0; top < limit -1; top++)
       for (search = top + 1; search < limit; search++)
            if (array[search] > array[top])
            {
                 temp = array[search];
                 array[search] = array[top];
                 array[top] = temp;
            }
}

/* print.c -- prints an array */
void print(const int array[], int limit)
{
   int index;

   for (index = 0; index < limit; index++)
   {
      printf("%2d ", array[index]);
      if (index % 10 == 9)
         putchar('\n');
   }
   if (index % 10 != 0)
      putchar('\n');
}

PE 12-7

/* pe12-7.c  */
#include <stdio.h>
#include <stdlib.h>  /* for srand() */
#include <time.h>    /* for time()  */
int rollem(int);

int main(void)
{
    int dice, count, roll;
    int sides;
    int set, sets;
    
    srand((unsigned int) time(0));  /* randomize rand() */
    
    printf("Enter the number of sets; enter q to stop.\n");
    while ( scanf("%d", &sets) == 1)
    {
          printf("How many sides and how many dice?\n");
        scanf("%d %d", &sides, &dice);
        printf("Here are %d sets of %d %d-sided throws.\n", sets, dice,
                sides);
        for (set = 0; set < sets; set++)
        {
            for (roll = 0, count = 0; count < dice; count++)
                roll += rollem(sides);
                /* running total of dice pips */
            printf("%4d ", roll);
            if (set % 15 == 14)
                putchar('\n');
        }
        if (set % 15 != 0)
            putchar('\n');
        printf("How many sets? Enter q to stop.\n");
    }
    printf("GOOD FORTUNE TO YOU!\n");
    return 0;
}

int rollem(int sides)
{
    int roll;

    roll = rand() % sides + 1;
    return roll;
}

Chapter 13

PE 13-2

/* Programming Exercise 13-2 */
#include <stdio.h>
#include <stdlib.h>
//#include <console.h>    /* Macintosh adjustment */


int main(int argc, char *argv[])
{
    int byte;
    FILE * source;
    FILE * target;
    
//    argc = ccommand(&argv);   /* Macintosh adjustment */

    if (argc != 3)
    {
        printf("Usage: %s sourcefile targetfile\n", argv[0]);
        exit(EXIT_FAILURE);
    }
    

    if ((source = fopen(argv[1], "rb")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[1]);
        exit(EXIT_FAILURE);
    }
    if ((target = fopen(argv[2], "wb")) == NULL)
    {
        printf("Could not open file %s for output\n", argv[2]);
        exit(EXIT_FAILURE);
    }
    while ((byte = getc(source)) != EOF)
    {
        putc(byte, target);
    }
    if (fclose(source) != 0)
        printf("Could not close file %s\n", argv[1]);
    if (fclose(target) != 0)
        printf("Could not close file %s\n", argv[2]);
        
    return 0;
}

PE 13-4

/* Programming Exercise 13-4 */
#include <stdio.h>
#include <stdlib.h>
#include <console.h>    /* Macintosh adjustment */


int main(int argc, char *argv[])
{
    int byte;
    FILE * source;
    int filect;
    
    argc = ccommand(&argv);   /* Macintosh adjustment */  

    if (argc == 1)
    {
        printf("Usage: %s filename[s]\n", argv[0]);
        exit(EXIT_FAILURE);
    }
    
    for (filect = 1; filect < argc; filect++)
    {
        if ((source = fopen(argv[filect], "r")) == NULL)
        {
            printf("Could not open file %s for input\n", argv[filect]);    
            continue;
        }
        while ((byte = getc(source)) != EOF)
        {
            putchar(byte);
        }
        if (fclose(source) != 0)
            printf("Could not close file %s\n", argv[1]);
    }    
        
    return 0;
}

PE 13-5

/* Programming Exercise 13-5 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//#include <console.h>    /* Macintosh adjustment */

#define BUFSIZE 1024
#define SLEN 81
void append(FILE *source, FILE *dest);

int main(int argc, char *argv[])
{
    FILE *fa, *fs;
    int files = 0;
    int fct;
    
 //   argc = ccommand(&argv);   /* Macintosh adjustment */  

    if (argc < 3)
    {
        printf("Usage: %s appendfile sourcefile[s]\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    if ((fa = fopen(argv[1], "a")) == NULL)
    {
        fprintf(stderr, "Can't open %s\n", argv[1]);
        exit(EXIT_FAILURE);
    }
    if (setvbuf(fa, NULL, _IOFBF, BUFSIZE) != 0)
    {
        fputs("Can't create output buffer\n", stderr);
        exit(EXIT_FAILURE);
    }
    
    for (fct = 2; fct < argc; fct++)
    {
        if (strcmp(argv[fct], argv[1]) == 0)
            fputs("Can't append file to itself\n",stderr);
        else if ((fs = fopen(argv[fct], "r")) == NULL)
            fprintf(stderr, "Can't open %s\n", argv[fct]);
        else
        {
            if (setvbuf(fs, NULL, _IOFBF, BUFSIZE) != 0)
            {
                fputs("Can't create output buffer\n",stderr);
                continue;
            }
            append(fs, fa);
            if (ferror(fs) != 0)
                fprintf(stderr,"Error in reading file %s.\n",
                        argv[fct]);
            if (ferror(fa) != 0)
                fprintf(stderr,"Error in writing file %s.\n",
                        argv[1]);
            fclose(fs);
            files++;
            printf("File %s appended.\n", argv[fct]);
        }
    }
    printf("Done. %d files appended.\n", files);
    fclose(fa);

    return 0;
}

void append(FILE *source, FILE *dest)
{
    size_t bytes;
    static char temp[BUFSIZE]; // allocate once

    while ((bytes = fread(temp,sizeof(char),BUFSIZE,source)) > 0)
        fwrite(temp, sizeof (char), bytes, dest);
}

PE 13-7

/* Programming Exercise 13-7a */
/* code assumes that end-of-line immediately precedes end-of-file */

#include <stdio.h>
#include <stdlib.h>
#include <console.h>    /* Macintosh adjustment */

int main(int argc, char *argv[])
{
    int ch1, ch2;
    FILE * f1;
    FILE * f2;
    
    argc = ccommand(&argv);   /* Macintosh adjustment */  

    if (argc != 3)
    {
        printf("Usage: %s file1 file2\n", argv[0]);
        exit(EXIT_FAILURE);
    }
    if ((f1 = fopen(argv[1], "r")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[1]);    
        exit(EXIT_FAILURE);
    }
    if ((f2 = fopen(argv[2], "r")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[2]);    
        exit(EXIT_FAILURE);
    }
    ch1 = getc(f1);
    ch2 = getc(f2);
    
    while (ch1 != EOF || ch2 != EOF)
    {
        while (ch1 != EOF && ch1 != '\n') /* skipped after EOF reached */
        {
            putchar(ch1);
            ch1 = getc(f1);
        }
        if (ch1 != EOF)
        {
            putchar('\n');
            ch1 = getc(f1);
        }
        while (ch2 != EOF && ch2 != '\n') /* skipped after EOF reached */
        {
            putchar(ch2);
            ch2 = getc(f2);
        }

        if (ch2 != EOF)
        {
            putchar('\n');
            ch2 = getc(f2);
        }
    }
        
    if (fclose(f1) != 0)
        printf("Could not close file %s\n", argv[1]);    
    if (fclose(f2) != 0)
        printf("Could not close file %s\n", argv[2]);    
        
    return 0;
}

/* Programming Exercise 13-7b */
/* code assumes that end-of-line immediately precedes end-of-file */

#include <stdio.h>
#include <stdlib.h>
#include <console.h>    /* Macintosh adjustment */

int main(int argc, char *argv[])
{
    int ch1, ch2;
    FILE * f1;
    FILE * f2;
    
    argc = ccommand(&argv);   /* Macintosh adjustment */  

    if (argc != 3)
    {
        printf("Usage: %s file1 file2\n", argv[0]);
        exit(EXIT_FAILURE);
    }
    if ((f1 = fopen(argv[1], "r")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[1]);    
        exit(EXIT_FAILURE);
    }
    if ((f2 = fopen(argv[2], "r")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[2]);