#include
using namespace std;
void generate_subsequence(char *in,char *out, int i,int j){
//base case
if(in[i]=’\0’){
out[j]=’\0’;
cout<<out;
return;
}
//rec case
//include the current character
out[j]=in[i];
generate_subsequence(in,out,i+1,j+1);
generate_subsequence(in,out,i+1,j);
}
int main(){
char input[]=“abc”;
char output[10];
generate_subsequence(input,output,0,0);
return 0;
}