remove the duplicate character in a string

/***

remove the duplicate in an unsorted array and return its new length of array.

adapt to any unsorted array with the template table of range table.

***/

int findIdx(string s, unordered_map<int, bool> wmap, int index) {

       while(index < s.size()) {

              if(!wmap[s[index]]) return index;

              index++;

       }

       return index;

}

int removedup(string str) {

       if(str.size() < 2) return str.size();

       unordered_map<int, bool> wordmap;

       for(int i=0; i<256; i++) {

              wordmap[i] = false;

       }

       int i=0, index=0;

       while(i<str.size() && index<str.size()) {

              if(!wordmap[str[i]]) {

                     wordmap[str[i++]] = true;

                     index++;

              } else {

                     index = findIdx(str, wordmap, index);

                     if(index == str.size()) break;

                     swap(str[index], str[i]);

                     wordmap[str[i++]] = true;

              }

              if(index == str.size()-1) break;

       }

       return i;

}

void main() {

       string S = "aabaaaaaaa";

       int len = removedup(S);s

       cout<<"test"<<endl;

}