C string inverter

septiembre 26th, 2007 Posted in Generalidades
No Comments

Some friend of mine just asked me to write him a simple string inverter in C, meaning a little program which reads a string and outputs the same string in inverted order. For example:

Input: Hello, we are done!
Output: !enod era ew ,olleH

I honestly don’t know the use of it, but any way here is it. (Not tested, but it should work fine)

Read more to see the code or download it zipped.

I just wrote a quick & dirty PHP version as well. Download.

However, the PHP version could be simplified a lot (one line of code):

<?php
    echo strrev("Hello, we are done!");
?>

Here’s the C code:

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

struct list
 {
	char item;
	struct list *link;
 };

typedef struct list x;
	x *stack, *temp = NULL;

/* Pushes characters to the stack */
push(char data)
 {
	stack = (x *)malloc(sizeof(x));
	stack->item = data;
	stack->link = temp;
	temp = stack;
 }

/* Pops characters from the stack */
pop()
 {
	x *t;
	while(temp != NULL)
	 {
		printf("%c", temp->item);
		t = temp;
		temp = temp->link;
		free(t);
	 }
	printf(" ");
	temp = NULL;
 }

main()
 {
	int i;
	char string[30];
	clrscr();
	printf("\n Your text: ");
	gets(string);
	i = 0;
	printf("\n Inverted: ");
	while(string[i] != '\0')
	 {
		(isspace(string[i]) != 0) ? pop() : push(string[i]);
		i++;
	 }
	pop();
 }
, , , , ,
Read More