REVERSE STRING IN SPECIAL ORDER

Problem statement:
Given a string, that contains special character together with alphabets (‘a’ to ‘z’ and ‘A’
to ‘Z’), reverse the string in a way that special characters are not affected.

E.g.:
Input:
str = "a,b$c"

Output:
str = "c,b$a"

Note that $ and, are not moved anywhere.
Only sub-sequence "abc" is reversed

Input:
str = "Ab,c,de!$"

Output:
str = "ed,c,bA!$"

CODE:

#include <stdio.h>

#include<string.h>

int main()

{

    char a[100];

    scanf("%s",a);

    int i=0,j=strlen(a)-1;

    while(1)

        {

        char temp;

        if(i>j)

         { break;}

    if((a[i] >= 65 && a[i]<91  || a[i]>=97 && a[i]<=122) && (a[j] >= 65 && a[j]<91
                    || a[j]>=97 &&a[j]<=122))

          {
              temp=a[i];

              a[i]=a[j];

              a[j]=temp;

              j--;i++;

        }

        if(a[i] < 65 || a[i]>91  && a[i]<97 || a[i]>=122)

           i++;

        if ((a[j] < 65 || a[j]>91  && a[j]<97 || a[j]>=122))

          j--;

     

    

    }

    printf("%s",a);

    return 0;

}