Question

describe each lines for each functions

#include <stdio.h>

/*Method to find the length of String*/
int str_len(char str[])
{
int i=0;
int stringLength=0;
while(str[i]!='\0')
{
stringLength+=1;
i++;
}
return stringLength;
}

/*Method to reverse string in iterative manner*/
void simpleReverse(char* str)
{
int stringLength=str_len(str);
  
for(int i=0;i<stringLength/2;i++)
{
char temp=str[i];
str[i]=str[stringLength-i-1];
str[stringLength-i-1]=temp;
}
}

/*Method to reverse string in iterative manner*/
void recursiveReverse(char str[], int start, int end)
{
if( start < end )
{
//swap
char temp = str[start];
str[start] = str[end];
str[end] = temp;
recursiveReverse(str, ++start, --end);
}
}

/*Method to print string*/
void printString(char str[])
{
int i=0;
while(str[i]!='\0')
{
printf("%c",str[i]);
i++;
}
printf("\n");
}

int main()
{
/*
Part 1: Storing a String
*/
char buffer1[]={'t','h','i','s',' ','i','s',' ','t','h','e',' ','f','i','r','s','t',' ','b','u','f','f','e','r','\0'};
char buffer2[]={'t','h','i','s',' ','i','s',' ','t','h','e',' ','s','e','c','o','n','d',' ','b','u','f','f','e','r','\0'};
char buffer3[80];
/*User Input to string using scanf() and format specifier:%s*
scanf("%s",&buffer3) only accepts string till first space is encountered space
scanf(" %[^ ]s",&buffer3) for string with space
*/
scanf("%s",&buffer3); /**/
  
  
/*Part 2: assigning pointer to array*/
char *pBuffer=buffer3;
printString(buffer3);
  
/*Part 3*/
/*Buffer 3 before reversing*/
printf("String before reversing: \n");
printString(buffer3);
/*Reversing buffer3 using simpleReverse():Iterative Method*/
simpleReverse(buffer3);
/*Data of string is changed in memory.*/
printf(" String After Reversing \n");
/*Buffer 3 after reversing*/
printString(buffer3);
  
  
printf(" String Reverse Using Recursion: \n");
  
/*Reversing buffer2 using recursive approach*/
printf(" String before reversing: \n");
printString(buffer2);
/*Reversing String */
recursiveReverse(buffer2,0,str_len(buffer2)-1);
/*Data of string is changed in memory.*/
printf(" String after Reverse: \n");
printString(buffer2);
  

return 0;
}

Answer 1

Code-

#include <stdio.h>

/*Method to find the length of String*/

int str_len(char str[])

{

//variable i and stringLength declare

int i=0;

int stringLength=0;

//iterating str char array till it is not equal to '\0'

while(str[i]!='\0')

{

//count the total no of char in the array

stringLength+=1;

i++;

}

//return the string lenght

return stringLength;

}

/*Method to reverse string in iterative manner*/

void simpleReverse(char* str)

{

//calculate the string lenght from above method and store it in stringLength

int stringLength=str_len(str);

//iterating for loop till half length of string length

for(int i=0;i<stringLength/2;i++)

{//swaping position of the str array like first pos of char array will be swap with last element

char temp=str[i];

str[i]=str[stringLength-i-1];

str[stringLength-i-1]=temp;

}

}

/*Method to reverse string in iterative manner*/

void recursiveReverse(char str[], int start, int end)

{

//here we are passing the char array str and start is the start index of array and end is the last index of the array

if( start < end )

{

//swap the positioning of start and end index of the array

char temp = str[start];

str[start] = str[end];

str[end] = temp;

//now call the function recursiveReverse and increment the start index and decrement the end index

recursiveReverse(str, ++start, --end);

}

}

/*Method to print string*/

void printString(char str[])

{

int i=0;

//iterating through the str char array till the end index

while(str[i]!='\0')

{

//printing the at each index

printf("%c",str[i]);

i++;

}

printf("\n");

}

int main()

{

/*

Part 1: Storing a String

*/

char buffer1[]={'t','h','i','s',' ','i','s',' ','t','h','e',' ','f','i','r','s','t',' ','b','u','f','f','e','r','\0'};

char buffer2[]={'t','h','i','s',' ','i','s',' ','t','h','e',' ','s','e','c','o','n','d',' ','b','u','f','f','e','r','\0'};

char buffer3[80];

/*User Input to string using scanf() and format specifier:%s*

scanf("%s",&buffer3) only accepts string till first space is encountered space

scanf(" %[^ ]s",&buffer3) for string with space

*/

scanf("%s",&buffer3); /**/

/*Part 2: assigning pointer to array*/

char *pBuffer=buffer3;

printString(buffer3);

/*Part 3*/

/*Buffer 3 before reversing*/

printf("String before reversing: \n");

printString(buffer3);

/*Reversing buffer3 using simpleReverse():Iterative Method*/

simpleReverse(buffer3);

/*Data of string is changed in memory.*/

printf(" String After Reversing \n");

/*Buffer 3 after reversing*/

printString(buffer3);

printf(" String Reverse Using Recursion: \n");

/*Reversing buffer2 using recursive approach*/

printf(" String before reversing: \n");

printString(buffer2);

/*Reversing String */

recursiveReverse(buffer2,0,str_len(buffer2)-1);

/*Data of string is changed in memory.*/

printf(" String after Reverse: \n");

printString(buffer2);

return 0;

}

Screenshots -