编写程序实现对输入的字符串排序(不区分大小写)

编写程序实现对输入的字符串排序, 如果主函数传递了-n参数, 则按数字排序,否则按字符串排序.

同时,如果传递了-r参数,则降序, 否则升序.

同时,如果传递了-f参数,则不区分大小写

二. 程序源码

#include

#include

#include

#include

#define NUMERIC 1

#define DECR 2

#define FOLD 4

#define MAXLINES 5000

#define MAXLEN 1000

#define MAXSTORAGE 10000

char *lineptr[MAXLINES];

char lines[MAXSTORAGE];

int charcmp(char *, char *);

int numcmp(char *, char *);

int p_realines(char *lineptr[], int maxlines);

void p_qsort(void *v[], int left, int right, int(*comp)(void *, void *));

void p_writelines(char *lineptr[], int nlines, int order);

static char option = 0;

int main(int argc, char *argv[])

{

int nlines;

int c, rc = 0;

while (--argc > 0 && (*++argv)[0] == -)

{

while (c = *++argv[0])

{

switch(c) {

case f:

option |= FOLD;

break;

case n:

option |= NUMERIC;

break;

case r:

option |= DECR;

break;

default:

printf("sort: illegal option %c\n", c);

argc = 1;

rc = -1;

break;

}

}

}

if (argc)

printf("Usage: sort -fnr\n");

else {

if ((nlines = p_readlines(lineptr, MAXLINES)) > 0) {

if (option & NUMERIC)

p_qsort((void **)lineptr, 0, nlines-1,(int (*)(void *, void *))numcmp);

else if (option & FOLD)

p_qsort((void **)lineptr, 0, nlines-1,(int (*)(void *, void *))charcmp);

else

p_qsort((void **)lineptr, 0, nlines-1, (int (*)(void *, void *))strcmp);

p_writelines(lineptr, nlines, option & DECR);

} else {

printf("Input too big to sort!\n");

rc = -1;

}

}

system("pause");

return rc;

}

int charcmp(char *s, char *t)

{

for (; tolower(*s) == tolower(*t); s++, t++)

if (*s == \0)

return 0;

return tolower(*s) - tolower(*t);

}

int p_readlines(char *lineptr[], int maxlines)

{

int len, nlines;

char *p = lines, line[MAXLEN];

nlines = 0;

printf("Please input a string(# to end input): ");

while ((len = getline(line, MAXLEN)) > 0)

{

if (strcmp(line, "#\n") == 0)

break;

if (nlines >= maxlines || p + len >= lines + MAXSTORAGE)

return -1;

else {

line[len - 1] = \0;

strcpy(p, line);

lineptr[nlines++] = p;

p += len;

}

printf("Please input a string(# to end input): ");

}

return nlines;

}

void p_writelines(char *lineptr[], int nlines, int order)

{

int i;

if (order)

for (i = nlines -1; i >= 0; i--)

printf("%s\n", lineptr[i]);

else

for (i = 0; i < nlines; i++)

printf("%s\n", lineptr[i]);

printf("\n");

}

void swap(void *v[], int i, int j)

{

void *temp;

temp = v[i];

v[i] = v[j];

v[j] = temp;

}

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;

}

int numcmp(char *s1, char *s2)

{

double v1, v2;

v1 = atof(s1);

v2 = atof(s2);

if (v1 < v2)

return -1;

else if (v1 > v2)

return 1;

else

return 0;

}

void p_qsort(void *v[], int left, int right, int(*comp)(void *, void *))

{

int i, last;

if (left >= right)

return;

swap(v, left, (left + right) / 2);

last = left;

for (i = left + 1; i <= right; i++)

{

if ((*comp)(v[i], v[left]) < 0)

swap(v, ++last, i);

}

swap(v, left, last);

p_qsort(v, left, last - 1, comp);

p_qsort(v, last + 1, right, comp);

}