oj.uz

답안 #816876

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
816876 2023-08-09T07:11:20 Z t6twotwo Parking (CEOI22_parking) C++17
10 / 100
 59 ms 6820 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define FFOR(i,a,b,c) for(int i=(a);(c)>0?i<=(b):i>=(b);i+=(c))
#define FOOR(i,a,b) FFOR(i,a,(b)-1,1)
#define ROOF(i,a,b) FFOR(i,(b)-1,a,-1)
#define FOR(i,n) FOOR(i,0,n)
#define ROF(i,n) ROOF(i,0,n)
#define FORR(x,v) for(auto &x:v)
#define vc vector
#define sz(v) (int)((v).size())
#define bg begin()
#define en end()
#define em empty()
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define ppb pop_back()
#define eb emplace_back
#define bk back()
#define fr front()
#define pp pop()
#define all(v) (v).begin(),(v).end()
#define lla(v) (v).rbegin(),(v).rend()
#define f first
#define s second
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N,M;
    cin>>N>>M;
    vc<int> bot(M),top(M),x(N,-1),y(N),free;
    FOR(i,M){
        cin>>bot[i]>>top[i];
        bot[i]--,top[i]--;
        if(bot[i]!=-1) (x[bot[i]]==-1?x[bot[i]]:y[bot[i]])=i*2;
        if(top[i]!=-1) (x[top[i]]==-1?x[top[i]]:y[top[i]])=i*2+1;
        if(bot[i]==-1&&top[i]==-1) free.pb(i);
    }
    vc<pair<int,int>> ans;
    auto move=[&](int u,int v) {
        ans.eb(u,v);
        int a;
        if(top[u]!=-1){
            a=top[u];
            top[u]=-1;
        }else{
            a=bot[u];
            bot[u]=-1;
        }
        if(bot[v]==-1){
            (x[a]/2==u?x[a]:y[a])=v*2;
            bot[v]=a;
        }else{
            (x[a]/2==u?x[a]:y[a])=v*2+1;
            top[v]=a;
        }
    };
    auto good=[&](int a) {
        return (x[a]%2==1||top[x[a]/2]==-1)&&(y[a]%2==1||top[y[a]/2]==-1);
    };
    vc<bool> parked(N);
    FOR(i,N){
        if(x[i]%2==1&&y[i]%2==1){
            move(x[i]/2,free.bk);
            move(y[i]/2,free.bk);
            free.ppb;
        }
        if(x[i]/2==y[i]/2) parked[i]=1;
    }
    queue<int> q;
    FOR(i,N){
        if(!parked[i]&&good(i)){
            parked[i]=1;
            q.push(i);
        }
    }
    while(!q.em){
        int i=q.fr;q.pp;
        int a=x[i]/2;
        int b=y[i]/2;
        if(top[b]!=-1) swap(a,b);
        move(a,b);
        if(bot[a]!=-1){
            if(!parked[bot[a]]&&good(bot[a])){
                parked[bot[a]]=1;
                q.push(bot[a]);
            }
        }
    }
    FOR(i,N){
        if(!parked[i]){
            cout<<-1;
            return 0;
        }
    }
    cout<<sz(ans)<<"\n";
    for(auto[x,y]:ans){
        cout<<x+1<<" "<<y+1<<"\n";
    }
    return 6/22;
}

Subtask #1
0.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Incorrect 0 ms 316 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 43 ms 6392 KB Output is correct
2 Correct 59 ms 6820 KB Output is correct
3 Correct 31 ms 5312 KB Output is correct
4 Correct 30 ms 5264 KB Output is correct
5 Correct 54 ms 6708 KB Output is correct

Subtask #3
0.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 1 ms 468 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #4
0.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 1 ms 468 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #5
0.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 1 ms 468 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Incorrect 0 ms 316 KB Output isn't correct
5 Halted 0 ms 0 KB -