Recursion Subsequences

#1

this is my code

#include
#include
using namespace std;

int cnt=0;
void subsequences(string str,int i,int j,vectorv){

 if(str[i]=='\0'){
	 v.push_back('\0');
	 cnt++;
	 for(auto x:v){
		 cout<<x;
	 }
	 cout<<" ";
	 return;
 }


 subsequences(str,i+1,j,v);
 v.push_back(str[i]);
 subsequences(str,i+1,j+1,v);

}
int main() {
string str;
cin>>str;
vectorv;
subsequences(str,0,0,v);
cout<<endl<<cnt;
return 0;
}

#2

there are some mistakes in your code

  1. no need to use vector ,string can be better suited
  2. after pushing element you also have to pop

check the modified Code below
Modified Code

#include<iostream>
#include<vector>
using namespace std;

int cnt = 0;
void subsequences(string str, int i, int j, string out) {
	if (str[i] == '\0') {
		cnt++;
		cout<<out<<" ";
		return;
	}

	subsequences(str, i + 1, j, out);
	out.push_back(str[i]);
	subsequences(str, i + 1, j + 1, out);
	out.pop_back();
}
int main() {
	string str;
	cin >> str;
	vector<char>v;
	subsequences(str, 0, 0, "");
	cout << endl << cnt;
	return 0;
}
#3

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