c programing Write a program to read in a string from the ke

c programing

Write a program to read in a string from the keyboard and display the whole string backwards.

Solution

#include<stdio.h>

void String_backwards(char str[],int count)
{
   //these variables are used for loop while swaping characters of String str
   int i, j;
   // temp will store character of String str while swapping
   char temp;

   /*
   * Below we swap the first character of the string str with the last character
   * of the String str
   * str[i] start from first char, as i value is 0 and str[j] start from last char, i.e., count,
   * str[i] and str[j] values are swapped using temp variable
   * and then we increase i by 1 and decrease j by 1.
   * This process run until the condition i < j becomes false.
   */
   for(i=0, j = count; i < j; i++, j--)
       {
           temp = str[i]; // temp will have ith character of string str, i.e., str[i]
           str[i] = str[j]; // str[i] and str[j] will be swapped
           str[j] = temp; // str[i] will get the character stored in temp
       }

   //Here we run a for loop to traverse the string of characters
   //and display the String character by character
   for (i = 0; i < count ; i++){
       printf(\"%c\", str[i]); //Printing each character
   }
}

int main(void)
{
   // This is an array of type char to hold the string entered by user. Size is 50, which can be modified as per use
   char str[50];
   // This variable is of type integer. This variable will be used to count the number of characters of the String entered by user
   int count;

   //Asking the user to enter the String
   printf(\"Please enter the String that is to be displayed backwards\ \");
  
   //Running a for loop to read character by character of String using getchar() method
   //count is initially set to 0 , which will increase on each character read
   for(count=0; (str[count]=getchar()) != \'\ \'; ++count);
  
   //We are calling String_backwards function to do the display the string backwards
   //str and count are two variables passed for the working of the function
   String_backwards(str, count);

   return 0;
}

The above solution uses for loops and swapping method. Same problem can be solved using recursion and pointers. I would suggest to try the other techniques also.

In case of any query related to the solution, feel free to ontact.

Thanks.