Code-Bin #442

untitled C Code
Posted by: dan | January 2, 2010 @ 10:41pm

C Code

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

#define MAXLEN 1000
#define MAXLINES 5000

char *lineptr[MAXLINES];

void writelines(char *[], int nlines);
void writelines1(char *[], int nlines);
int readlines(char *[], int);
int readlines1(char *[], int);

void qsort(char *[], int, int);

main()
{
	int nlines;
	char line[MAXLEN];
	char *lines[MAXLINES];
	
	//read lines and print them
	while ((nlines = readlines1(lines, MAXLINES)) > 0)
		writelines(lines, nlines);
}

//print input lines
void writelines(char *lines[], int nlines)
{
	int i;
	
	for (i = 0; i < nlines; ++i) 
		printf("%s\n", lines[i]);
}

//print input lines
void writelines1(char *lines[], int nlines)
{
	int i;
	
	for (i = 0; i < nlines; ++i) 
		printf("%s\n", lines[i]);
}

void my_strcpy(char *, char *);
int readline(char [], int);
char *alloc(int);

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

nlines = 0;
	while ((len = readline(line, MAXLEN)) > 0)	
		if (nlines >= maxlines || (p = alloc(len)) == NULL)
			return -1;
		else {
			line[len-1] = '\0';
			my_strcpy(p, line);
			lines[nlines++] = p;
		}
	return nlines;
}

//get input lines
int readlines1(char *lines[], int maxlines)
{
	int len, nlines;
	char *p, line[MAXLEN];
	char b[MAXLEN];
	
	p = b;
	nlines = 0;
	while ((len = readline(line, MAXLEN)) > 0)
		if (nlines >= maxlines)
			return -1;
		else {
			line[len-1] = '\0';
			my_strcpy(p, line);
			lines[nlines++] = p;
		}
	return nlines;
}

//copy t to s
void my_strcpy(char *s, char *t)
{
	while (*t != '\0')
		*s++ = *t++;
	*s = '\0';
}

//get input line
int readline(char s[], int max)
{
  int c, i;

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

#define ALLOCSIZE 1000

static char allocbuf[ALLOCSIZE];
static char *allocp = allocbuf;

//allocate storage
char *alloc(int n)
{
	if (allocbuf + ALLOCSIZE - allocp >= n) {
		allocp += n;
		return allocp - n;
	} 
	else
		return 0;
}

int my_strcmp(char *, char *);
void swap(char *[], int, int);

//quicksort lines
void qsort(char *v[], int left, int right)
{
	int i, last;

if (left >= right)
		return;
	swap(v, left, (left + right) / 2);
	last = left;
	for (i = left + 1; i <= right; ++i)
		if (my_strcmp(v[i], v[left]) < 0)
			swap(v, ++last, i);
	swap(v, left, last);
	qsort(v, left, last - 1);
	qsort(v, last + 1, right);
}

//compare lines 
int my_strcmp(char *s, char *t)
{
	while (*s == *t) { 
		++s, ++t;
		if (*s == '\0') 
			return 0;
	}
	return *s - *t;
}

//swap lines
void swap(char *v[], int i, int j)
{
	char *temp = v[i];
	v[i] = v[j];
	v[j] = temp;
}

Syntax Highlighting

[Open in new window]

Author Comments

none

Rating

4.73 / 8
45 Votes