oj.uz

Submission #817235

# Submission time Handle Problem Language Result Execution time Memory
817235 2023-08-09T10:52:09 Z t6twotwo Parking (CEOI22_parking) C++17
50 / 100
 98 ms 8672 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(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;
        if(top[i]==-1){
            // if((x[k]%2==0&&y[k]%2==0&&top[x[k]/2]==-1&&top[y[k]/2]==-1)) while(1){};
        }
        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){
            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 0 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 0 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 212 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 Incorrect 45 ms 4676 KB Output isn't correct
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 0 ms 212 KB Output is correct
3 Correct 0 ms 340 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 212 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 0 ms 212 KB Output is correct
3 Correct 0 ms 340 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 212 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 98 ms 8600 KB Output is correct
11 Correct 27 ms 3284 KB Output is correct
12 Correct 34 ms 3372 KB Output is correct
13 Correct 66 ms 7620 KB Output is correct
14 Correct 32 ms 3448 KB Output is correct
15 Correct 31 ms 3284 KB Output is correct
16 Correct 80 ms 8672 KB Output is correct
17 Correct 31 ms 3320 KB Output is correct
18 Correct 76 ms 8208 KB Output is correct

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 340 KB Output isn't correct
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 0 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 0 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 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Incorrect 45 ms 4676 KB Output isn't correct
12 Halted 0 ms 0 KB -