1 min read
https://www.geeksforgeeks.org/print-subsequences-string/
void printSubsequence(string input, string output) {
if (input.empty()) {
cout << output << endl;
return;
}
printSubsequence(input.substr(1), output + input[0]);
printSubsequence(input.substr(1), output);
}
// printSubsequence(input, "");