Submission #640495

#	Time	Username	Problem	Language	Result	Execution time	Memory
640495		Urvuk3	Xor Sort (eJOI20_xorsort)	C++17	65 / 100	11 ms	1080 KiB

xorsort

#include <bits/stdc++.h>

using namespace std;

#define ll long long
const int INF=1e9;
const ll LINF=1e18;
#define fi first
#define se second
#define pii pair<int,int>
#define mid ((l+r)/2)
#define sz(a) (int((a).size()))
#define all(a) a.begin(),a.end()
#define endl "\n"
#define PRINT(x) cerr<<#x<<'='<<x<<endl;
#define pb push_back
#define PRINTvec(niz) { cerr<<#niz<<"="; for(auto _i:niz) cerr<<_i<<" "; cerr<<endl; }

void Solve(){
    int N,S; cin>>N>>S;
    bool subtask1=(2<=N && N<=150 && S==1);
    bool subtask2=(2<=N && N<=200 && S==1);
    bool subtask3=(2<=N && N<=1000 && S==2);
    vector<int> a(N+1); for(int i=1;i<=N;i++) cin>>a[i];
    vector<pii> opers;

    function<void(int,int)> Oper=[&](int i,int j){
        if(abs(i-j)==1) a[i]=a[i]^a[j];
        opers.pb({i,j});
    };
    function<bool(int,int)> Has=[&](int x,int bit){
        return (x&(1<<bit))>0;
    };

    if(subtask1){
        for(int i=1;i<=N;i++){
            for(int j=1;j<=N-1;j++){
                if(a[j]>a[j+1]){
                    Oper(j,j+1);
                    Oper(j+1,j);
                    Oper(j,j+1);
                }
            }
        }
    }
    else if(subtask2){

    }
    else if(subtask3){
        set<int> s;
        function<void(int,int,int)> Update=[&](int i,int j,int bit){
            if(!Has(a[i],bit) && s.count(i)) s.erase(i);
            if(!Has(a[j],bit) && s.count(j)) s.erase(j);
            if(Has(a[i],bit)) s.insert(i);
            if(Has(a[j],bit)) s.insert(j);
        };

        int L=1,R=N;
        for(int bit=20;bit>=0;bit--){
            s.clear();
            bool pomeren=false;
            for(int i=L;i<=R;i++){
                if(Has(a[i],bit)){
                    s.insert(i);
                    pomeren=true;
                }
            }
            while(!s.empty() && !(sz(s)==1 && s.count(R))){
                int i=*(s.begin());
                if(Has(a[i+1],bit)){
                    Oper(i,i+1); Update(i,i+1,bit);
                }
                else{
                    Oper(i+1,i); Update(i,i+1,bit);
                    Oper(i,i+1); Update(i,i+1,bit);
                }
            }
            if(pomeren) --R;
        }
    }
    cout<<sz(opers)<<endl;
    for(auto p:opers) cout<<p.fi<<" "<<p.se<<endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t;
    //cin>>t;
    t=1;
    while(t--){
        Solve();
    }
    return 0;
}

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