Swap 2 characters in a sentence which is adjacent to white space

Question

It should be work for Dynamic input

For Example
Input: Hello Good to See You
Output: HellG ooot dS oeY eou

Comments

Nice Question.... (y) (y)

Answer 1

Check the following Code

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

static inline void swap(char *a, char *b){
        char ch = *a;
        *a = *b;
        *b = ch;
}

char *wordTop(char *s){
        while(*s && isspace(*s))
                ++s;
        return *s ? s : NULL;
}

char *wordTail(char *s){
        char *p;
        do{
                p = s++;
        }while(*s && !isspace(*s));
        return p;
}

int main(){
        char *input;
        char *top, *tail;

        input = malloc(255);

        printf("Enter the Input\n");
        gets(input);
        top = input;
        for(;;){
                tail = wordTail(wordTop(top));
                if((top = wordTop(tail+1)))
                        swap(top, tail);
                else
                        break;
        }
        printf("\n%s\n", input);
}

Input:
My Name is Pardeep

Output:
MN yami eP sardeep

Comments

I am giving solution in the Java.Please look....
public class swap {

    public static void main(String[] args) {
        String input = "Hello Good to See You";
        char chracters[] = new char[]{};
        if (input != null && !input.isEmpty()) {
            chracters = input.toCharArray();
            for (int i = 0; i < chracters.length; i++) {
                if (i > 0 && chracters[i] == ' ') {
                    char tempChar = chracters[i - 1];
                    chracters[i - 1] = chracters[i + 1];
                    chracters[i + 1] = tempChar;
                }
            }
        }
       
        for (int i = 0; i < chracters.length; i++) {
            System.out.print(chracters[i]);
        }   
    }

}

input = "Hello Good to See You"
output = HellG ooot dS oeY eou

---

is this possible to without using pointers.can give me solution without using pointers.

Answer 2

#include<stdio.h>
void swap(char *str)
{
    char temp;
    char *p, *q;
    p=str;
    while(*p)
    {
          if( *p != ' ' && *(p+1) == ' ')
          {
             q = p;
          }  
          if(*(p-1) == ' ' && *p != ' ')
          {
               temp = *q;
               *q = *p;
                *p = temp;
          } 
         p++;
    }
}

int main(void)
{
     char string[255];
     printf("Enter the String \n");
     gets(string);
     swap(string);
     printf("output string :\n");
     printf("%s\n", string);
     return 0;
}

Comments

is this possible to without using pointers.can give me solution without using pointers.

---

Yes. It is possible, we have to do small modifications inside swap functions.

void swap(char *str)
{
   char temp; int i,j;
    i=0;
    while(str[i])
    {
          if(str[i] != ' ' && str[i+1] ==' ')
                   j =i;
          if(str[i-1] == ' ' && str[i] != ' ')
           {
                    temp = str[j];
                    str[j] = str[i];
                    str[i] = temp;
           }
            i++;
     }
}

please check this one.