oj.uz

Submission #640460

# Submission time Handle Problem Language Result Execution time Memory
640460 2022-09-14T17:35:03 Z Urvuk3 Xor Sort (eJOI20_xorsort) C++17
0 / 100
 1 ms 212 KB 
#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;
    vector<int> a(N+1); for(int i=1;i<=N;i++) cin>>a[i];
    set<int> s;
    vector<pii> opers;

    function<void(int,int)> Oper=[&](int i,int j){
        a[i]=a[i]^a[j];
        opers.pb({i,j});
    };
    function<bool(int,int)> Has=[&](int x,int bit){
        return (x&(1<<bit))>0;
    };
    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;
    if(S==2){
        for(int bit=20;bit>=0;bit--){
            s.clear();
            for(int i=L;i<=R;i++){
                if(Has(a[i],bit)){
                    s.insert(i);
                }
            }
            while(!s.empty() && !(sz(s)==1 && s.count(L))){
                int i=*(prev(s.end()));
                if(Has(a[i-1],bit)){
                    Oper(i,i-1); Update(i-1,i,bit);
                }
                else{
                    Oper(i-1,i); Update(i-1,i,bit);
                    Oper(i,i-1); Update(i-1,i,bit);
                }
            }
            ++L;
        }
    }
    else{
        for(int bit=20;bit>=0;bit--){
            s.clear();
            for(int i=L;i<=R;i++){
                if(Has(a[i],bit)){
                    s.insert(i);
                }
            }
            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);
                }
            }
            --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
0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 212 KB Not sorted
2 Halted 0 ms 0 KB -

Subtask #2
0 / 35.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 212 KB Not sorted
2 Halted 0 ms 0 KB -

Subtask #3
0 / 40.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 212 KB Not sorted
2 Halted 0 ms 0 KB -