HackerEarth Remove Duplicates problem solution

In this HackerEarth Remove Duplicates problem solution Given a string S. Your task is to remove all duplicates characters from the string S

HackerEarth Remove Duplicates problem solution.

#include <bits/stdc++.h>
using namespace std;
int main()
{
  string a;
  cin>>a;
  int Hash[26]={0};
  for(int i=0;i<a.size();i++)
    if(!Hash[a[i]-'a'])
      Hash[a[i]-'a']=1;
  for(int i=0;i<a.size();i++){
    if(Hash[a[i]-'a']){
      cout<<a[i];
      Hash[a[i]-'a']=0;
    }
  }
  cout<<endl;
  return 0;
}