Submission

Score: 90

User: dddrrrr

Problemset: สุ่มสลับ

Language: cpp

Time: 0.197 second

Submitted On: 2025-10-14 11:00:20

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

string s;
int cnt = 0;
bool found = false;
void backtrack(string& str ,string& tmp ,vector <bool>& chosen){
	if(found)return ;
	if(tmp.size() == str.size()){
		cnt++;
		if(tmp == s){
			cout << cnt;
			found = true;
		}
		return ;
	}
	
	for(int i=0 ;i<str.size() ;i++){
		if(chosen[i])continue;
		
		tmp += str[i];
		chosen[i] = true;
		backtrack(str ,tmp ,chosen);
		
		tmp.pop_back();
		chosen[i] = false;
	}
}

int main(){
	cin.tie(0)->sync_with_stdio(0);
	int n;cin >> n;
	string str ;cin >> str;
	s = str;
	
	sort(str.begin() ,str.end());
	
	vector <bool> chosen(str.size() ,false);
	string tmp="";
	backtrack(str ,tmp ,chosen);
	return 0;
}