In this post, we are going to solve Unique String DSA Problem from Amazon’s 10th October Online assessment. Let’s have a look at the problem statement first and then try to solve the problem.
Unique String DSA Problem Statement
Given a string s that contains characters from a to z returns the smallest subsequence of s that contains all distinct characters of ‘s’ exactly once.
Input
The first line of input contains a single string S (
)
Output
For each output print the smallest subsequence of s that doesn’t contain duplicates
Example
Input
bcabc
Output
abc
Problem Solution in C++
#include <bits/stdc++.h>
using namespace std;
int main() {
string s;
cin>>s;
set<char> st;
for(auto it:s) st.insert(it);
s="";
for(auto it:st) s+=it;
cout<<s<<endl;
return 0;
}