Permutation_sequence_With_case_change_wihtalha_unmeric_Aharacter.cpp

#include<bits/stdc++.h>
using namespace std;

void solve(string ip,string op,vector<string> &v ){
	if(ip.size() == 0){
		v.push_back(op);
		return;
	}

	if(!isdigit(ip[0])){
		string op1 = op;
		string op2 = op;
		op1.push_back(tolower(ip[0]));
		op2.push_back(toupper(ip[0]));
		ip.erase(ip.begin() + 0);
		solve(ip,op1,v);
		solve(ip,op2,v);
	}else{
		string op1 = op;
		op1.push_back(ip[0]);
		ip.erase(ip.begin() + 0);
		solve(ip,op1,v);
	}
}

int main(){
	string ip = "a1b2c3";
	string op = "";
	vector<string> v;
	solve(ip,op,v);
	for(auto i : v){
		cout<<i<<" "<<endl;
	}
}