problem driving me insane!!

hi, im in advanced computer science in school, and i have this horrible problem, i can't seem to stop my brain from boggling over it for days.

how do i remove duplicates out of a string!!???


if i input this string, "4751244"

i need to output 1 2 4 5 7 as the numbers that the string is made of.

i can sort the string, so the string is 1244457 sorted, now i need someway to check to see if the string has duplicates and remove it!

please post a source or help me understand! here is what i have so far!

void Integer :: digits()
{
int countplace = 0;
int placeCount = 0;
int temp = 0;
int minIndex = 0;
int a = 0;
apstring mynum2 = mynum;

for(int counter = 0; counter < mynum2.length() - 1; counter++)
{
minIndex = counter;

for(placeCount = counter + 1; placeCount < mynum2.length(); placeCount++)
{
if(mynum2[placeCount] < mynum2[minIndex])
minIndex = placeCount;
}

temp = mynum2[minIndex];
mynum2[minIndex] = mynum2[counter];
mynum2[counter] = temp;

}



apstring mynum3 = " ";
for(int i = 0; i < mynum2.length() - 1; i++)
{
if(mynum2[i] == mynum2[i+1])
a = 1;
if (a == 0)
{

mynum3 += mynum2[i];
mynum3 += mynum2[i+1];
a = 0;
}

a = 0;

}
cout << mynum3;

}

use pointers.
ansi c version --

Code:

---

#include <stdio.h>
#include <string.h>

int main(int argc, char* argv[])
{
                char tmp[20];
                char n[20];
                strcpy(n,"0011233445566789");
                memset(tmp,'\0',sizeof(tmp) ); // this avoids placing zero at end of string
                dedupe(tmp,n);
                printf("%s\n",tmp);
                return 0;
}

void dedupe(char *ret, char *in){
      char *a,*b,*c;
          c=ret;
          a=in;
          b=a+1;
          while (*a!='\0'){
                  if(*a != *b) *c++=*a;
                  a++;
                  b++;
          }
       

}

---

thanx