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Submission #817253

# Submission time Handle Problem Language Result Execution time Memory
817253 2023-08-09T11:03:44 Z t6twotwo Parking (CEOI22_parking) C++17
50 / 100
 87 ms 8668 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;
        }
        if(bot[u]==-1){
            free.pb(u);
        }
    };
    auto park=[&](int i){
        int a=x[i]/2;
        int b=y[i]/2;
        if(a==b)return;
        if(top[a]!=-1&&top[b]!=-1) return;
        if(x[i]%2==1&&y[i]%2==1) return;
        if(x[i]%2==0&&top[a]!=-1) return;
        if(y[i]%2==0&&top[b]!=-1) return;
        if(top[b]!=-1) swap(a,b);
        move(a,b);
    };
    auto get=[&](){
        if(free.em){
            cout<<-1;
            exit(0);
        }
        int t=free.bk;
        free.ppb;
        return t;
    };
    FOR(i,M){
        if(top[i]==-1&&bot[i]!=-1){
            int j=i,k=bot[i];
            while(x[k]%2!=y[k]%2){
                j^=(x[k]/2)^(y[k]/2);
                park(k);
                k=bot[j];
            }
        }
    }
    FOR(i,N) park(i);
    FOR(i,N) {
        if((x[i]%2==0&&y[i]%2==0&&top[x[i]/2]==-1&&top[y[i]/2]==-1)) while(1){};
    }
    vc<bool> vis(M);
    FOR(i,M){
        if(vis[i]||bot[i]==top[i])continue;
        vis[i]=1;
        int k=bot[i],f=0,j=top[i]==-1?(i^(x[k]/2)^(y[k]/2)):i;
        vc<int> S{k};
        vc<vc<int>> T;
        while(1){
            T.pb({});
            vis[j]=1;
            k=f?bot[j]:top[j];
            while(k!=-1&&k!=bot[i]&&x[k]%2!=y[k]%2){
                T.bk.pb(k);
                j^=(x[k]/2)^(y[k]/2);
                vis[j]=1;
                k=f?bot[j]:top[j];
            }
            if (k==bot[i]||k==-1)break;
            S.pb(k);
            j^=(x[k]/2)^(y[k]/2);
            f^=1;
        }
        if(top[i]==-1){
            assert(sz(S)!=1);
            FFOR(j,1,sz(S)-2,2){
                int t=get();
                move(x[S[j]]/2,t);
                move(y[S[j]]/2,t);
                ROF(k,sz(T[j-1])) park(T[j-1][k]);
                FOR(k,sz(T[j])) park(T[j][k]);
                park(S[j-1]);
            }
            park(S.bk);
        }else{
            if (sz(S)==1){
                int t=get();
                int a=x[S[0]];
                int b=y[S[0]];
                if (a%2==0) swap(a,b);
                move(a/2,t);
                ROF(j,sz(T[0])) park(T[0][j]);
                move(b/2,t);
                continue;
            }
            int t=get();
            move(x[S[1]]/2,t);
            move(y[S[1]]/2,t);
            ROF(j,sz(T[0])) park(T[0][j]);
            FOR(j,sz(T[1])) park(T[1][j]);
            FFOR(j,3,sz(S)-1,2){
                int t=get();
                move(x[S[j]]/2,t);
                move(y[S[j]]/2,t);
                ROF(k,sz(T[j-1])) park(T[j-1][k]);
                FOR(k,sz(T[j])) park(T[j][k]);
                park(S[j-1]);
            }
            park(S[0]);
            if(sz(S)%2){
                ROF(j,sz(T.bk)) park(T.bk[j]);
                park(S.bk);
            }
        }
    }
    cout<<sz(ans)<<"\n";
    for(auto[x,y]:ans){
        cout<<x+1<<" "<<y+1<<"\n";
    }
    return 6/22;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 256 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 29 ms 6988 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 340 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 81 ms 8616 KB Output is correct
11 Correct 28 ms 3284 KB Output is correct
12 Correct 31 ms 3284 KB Output is correct
13 Correct 80 ms 7516 KB Output is correct
14 Correct 32 ms 3412 KB Output is correct
15 Correct 31 ms 3324 KB Output is correct
16 Correct 87 ms 8668 KB Output is correct
17 Correct 38 ms 3320 KB Output is correct
18 Correct 76 ms 8192 KB Output is correct

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Runtime error 1 ms 468 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 256 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Runtime error 29 ms 6988 KB Execution killed with signal 6
12 Halted 0 ms 0 KB -