Sorting

#include <bits/stdc++.h>
 
using namespace std;
 
#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define per(i, a, b) for (int i = a - 1; i >= (b); --i)
#define trav(a, x) for (auto &a : x)
 
#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define pb push_back
 
#define umap unordered_map
#define uset unordered_set
#define INF 1000000000
 
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef long long ll;
 
int main() {
    ios::sync_with_stdio(0);
    cin.tie(NULL);
 
    uset<string> vis;
    int tc, n;
    cin>>tc;
    while(tc--){
        cin>>n;
        string nums(n, 0);
        rep(i,0,n)cin>>nums[i];
 
        queue<string>q;
        q.push(nums);
        vis.insert(nums);
        string ans = "NO", goal = string(n, ' ');
        rep(i,0,n)goal[i]='1'+i;
 
        while(!q.empty()){
            nums = q.front();
            q.pop();
            if(nums==goal) {
                ans = "YES";
                while (!q.empty()) q.pop();
                continue;
            }
 
            rep(i,0,n-3) {
                string next;
                rep(j,i+2,n-1){
                    next = nums;
                    swap(next[i],next[j]);
                    swap(next[i+1],next[j+1]);
                    if(!vis.count(next)){
                        vis.insert(next);
                        q.push(next);
                    }
                }
            }
        }
 
        cout<<ans<<'\n';
        vis.clear();
    }
    return 0;
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 3

Group: 1, 2

Verdict: ACCEPTED

Test 4

Group: 1, 2

Verdict: TIME LIMIT EXCEEDED