/*Program to reverse the given string*/
#include<stdio.h>

#define MAXCH 100

void revstr(char *);

int main()
{
	char arr[MAXCH];
	*arr=' ';
	*(char *)(arr+1)='\0';
	while(strcmp(arr,"")!=0)
	{
		printf("Enter the string (null string to terminate): ");
		fgets(arr,MAXCH,stdin);
		*(char *)(arr+strlen(arr)-1)='\0';
		puts(arr);
		revstr(arr);
		if(strcmp(arr,"")!=0)
			puts("Reversed string: ");
		puts(arr);
	}
	return 0;
}

/*Usage:	revstr(char *str)
	Return value: void
	Arguments: pointer to array of characters
	Reverses the order of the array contents*/
/*Assumed that string is null terminated*/
void revstr(char *arr)
{
	char *p,*q;
	char *tmp=(char *)(malloc(sizeof(char)*strlen(arr)));
	for(p=(char *)(arr+strlen(arr)-1),q=tmp;p>=arr;p--,q++)
		*q=*p;	
	*(char *)(q+strlen(arr))='\0';
	strcpy(arr,tmp);
}