Submission #1127662

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127662		Zbyszek99	Xor Sort (eJOI20_xorsort)	C++20	25 / 100	8 ms	1476 KiB

xorsort

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
//using namespace __gnu_pbds;
using namespace std;
//typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll rand(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //random();
    int n,t;
    cin >> n >> t;
    vector<pii> ans;
    vector<int> arr(n+1);
    rep(i,n) cin >> arr[i+1];
    if(t == 1)
    {
        rep(i,n)
        {
            pii min_elm = {1e9,-1};
            rep2(j,i,n-1)
            {
                min_elm = min(min_elm,{arr[j+1],j+1});
            }
            int cur = min_elm.ss;
          //  cout << cur << " " << min_elm.ff << " cur\n";
            while(cur != i+1)
            {
                ans.pb({cur-1,cur});
                ans.pb({cur,cur-1});
                ans.pb({cur-1,cur});
                swap(arr[cur-1],arr[cur]);
                cur--;
            }
        }
    }
    if(t == 2)
    {
        for(int bit = 19; bit >= 0; bit--)
        {
            bool was = false;
    //        cout << bit << " bit\n";
            rep2(i,1,n)
            {
                if(arr[i] & (1 << bit))
                {
      //              cout << i << " V\n";
                    was = true;
                    int cur = i-1;
                    while(cur >= 1 && (arr[cur] & (1 << bit)) == 0)
                    {
                        ans.pb({cur,cur+1});
                        arr[cur] ^= arr[cur+1];
                        cur--;
                    }
                    cur = i+1;
                    while(cur <= n && (arr[cur] & (1 << bit)) == 0)
                    {
                        ans.pb({cur,cur-1});
                        arr[cur] ^= arr[cur-1];
                        cur++;
                    }
                }
            }
            if(was)
            {
                rep2(i,2,n)
                {
                    ans.pb({i-1,i});
                    arr[i-1] ^= arr[i];
                }
            }
        }
    }
    //reverse(all(ans));
    cout << siz(ans) << "\n";
    forall(it,ans)
    {
        cout << it.ff << " " << it.ss << "\n";
    }
}

• Subtask 1: 25 / 25
• Subtask 2: 0 / 35
• Subtask 3: 0 / 40