Chapter 1, Problem 6C

Program code:

//include the required header files

#include <stdio.h>

#include <string.h>

//define a function swap()

void swap(char *a, char *b)

{

//declare a character variable temp

char temp;

//swaping

temp = *a;

*a = *b;

*b = temp;

}

//define a function all()

void all(char *seq, int one, int two)

{

//create an integer variable i

int i;

//if the condition is true

if (one == two)

//print the print the string

printf("%s ", seq);

//if the condition is not true

else

//iterate a for loop

for (i = one; i <= two; i++)

{

//call the method swap()

swap((seq+one), (seq+i));

//call the method all()

all(seq, one+1, two);

//call the method swap()

swap((seq+one), (seq+i));

}

}

//define main()

int main()

{

//declare a character array

char word[] = {'a','b','c','d','e','f'};

//get the length of the array

int n = strlen(word);

//call the method all

all(word, 0, n-1);

//return 0

return 0;

}

Explanation:

The above program snippet is used to implement find the combination of letters without repetition. In the code,

• Include the required header files.
• Define the function “swap()”...