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Submission #563741

# Submission time Handle Problem Language Result Execution time Memory
563741 2022-05-18T05:01:22 Z minhcool One-Way Streets (CEOI17_oneway) C++17
60 / 100
 3000 ms 115344 KB 
#include<bits/stdc++.h>
using namespace std;

#define int long long
#define fi first
#define se second
#define pb push_back

typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;

const int N = 3e5 + 5;
const int oo = 1e18 + 7, mod = 1e9 + 7;

int n, m, p;

vector<int> Adj[N], Adj2[N];
vector<ii> Adj3[N];

vector<ii> edges;

struct cmp{
    bool operator()(const ii& a, const ii& b)const{
        return a.fi > b.fi;
    }
};

set<ii> bridges;

int cnt;
int ti[N], low[N];

char ans[N];


map<ii, vector<int>> mp;
map<ii, vector<int>> mp2;

void dfs(int u, int p){
    cnt++;
    ti[u] = low[u] = cnt;
    for(auto v : Adj[u]){
        if(ti[v]){
            if(mp[{min(u, v), max(u, v)}].size() > 1) low[u] = min(low[u], ti[v]);
            if(v != p) low[u] = min(low[u], ti[v]);
        }
        else{
            dfs(v, u);
            low[u] = min(low[u], low[v]);
            if(ti[u] < low[v]){
                    //cout << u << " " << v << "\n";
                bridges.insert({min(u, v), max(u, v)});
            }
        }
    }
}

int cnt_comp;
int comp[N];

void dfs2(int u){
    //cout << u << "\n";
    comp[u] = cnt_comp;
    for(auto v : Adj2[u]){
        if(comp[v]) continue;
        dfs2(v);
    }
}

int sz[N], rt[N], answ[N];

vector<ii> que[N];
multiset<ii, cmp> ques[N];// for component

int sparse[N][20], d[N];
int ind[N];

void dfs3(int u, int p){
    //cout << "EDGE " << u << " " << ind[u] << "\n";
    for(auto it : Adj3[u]){
        int v = it.fi;
        if(v == p) continue;
        d[v] = d[u] + 1;
        sparse[v][0] = u;
        for(int i = 1; i <= 19; i++) sparse[v][i] = sparse[sparse[v][i - 1]][i - 1];
        //cout << v << "\n";
        //for(int i = 0; i <= 19; i++) cout << sparse[v][i] << " ";
        //cout << "\n";
        ind[v] = it.se + 1;
        dfs3(v, u);
    }
}

int lca(int x, int y){
    if(d[x] > d[y]) swap(x, y);
    //cout << x << " " << y << " " << d[x] << " " << d[y] << "\n";
    for(int i = 19; i >= 0; i--){
        if(d[y] >= (d[x] + (1LL << i))){
            //cout << i << "\n";
            y = sparse[y][i];
        }
    }
    assert(d[x] == d[y]);
    //cout << x << " " << y << "\n";
    if(x == y) return x;
    for(int i = 19; i >= 0; i--){
        if(sparse[x][i] != sparse[y][i]){
            x = sparse[x][i];
            y = sparse[y][i];
        }
    }
    return sparse[x][0];
}

int root(int x){
    return (x == rt[x] ? x : rt[x] = root(rt[x]));
}

void merge(int x, int y){
    x = root(x), y = root(y);
    if(x == y) return;
    if(sz[x] < sz[y]) swap(x, y);
    sz[x] += sz[y], rt[y] = x;
    //cout << ques[x].size() << " " << ques[y].size() << "\n";
    for(auto it : ques[y]) ques[x].insert(it);
    ques[y].clear();
}

void dfs4(int u, int p){
    for(auto it : Adj3[u]){
        int v = it.fi;
        if(v == p) continue;
        dfs4(v, u);
        merge(u, v);
    }
    //return;
    int temp = root(u);
    for(auto it : que[u]) ques[temp].insert(it);
    //if(u == 137) cout << ques[temp].size() << "\n";
    while(ques[temp].size() && (*ques[temp].begin()).fi >= d[u]) ques[temp].erase(ques[temp].begin());
    for(auto it : ques[temp]) assert(it.fi < d[u]);
    if(!ind[u]) return;
    if(ques[temp].size()){
        //cout << u << " " << p << " " << ind[u] << " " << temp << " " << ques[temp].size() << "\n";
        //cout << (*ques[temp].begin()).fi << " " << d[u] << "\n";
        bool x = (*ques[temp].begin()).se;
        answ[ind[u] - 1] = (!x ? u : p);
    }
    else{
        //if(ind[u] == 95) cout << u << "\n";
        //assert(ind[u] - 1 != 94);
        ans[ind[u] - 1] = 'B';
       // cout << ind[u] << "\n";
    }
}

void process(){
    cin >> n >> m;
    for(int i = 0; i < m; i++){
        int x, y;
        cin >> x >> y;
        edges.pb({x, y});
        mp[{min(x, y), max(x, y)}].pb(i);
        //Adj[x].pb(y);
        //Adj[y].pb(x);
    }
    for(auto it : mp){
        Adj[it.fi.fi].pb(it.fi.se);
        Adj[it.fi.se].pb(it.fi.fi);
        if(it.se.size() >= 2){
            //Adj[it.fi.fi].pb(it.fi.se);
            //Adj[it.fi.se].pb(it.fi.fi);
        }
    }
    for(int i = 1; i <= n; i++) if(!ti[i]) dfs(i, i);
    //for(auto it : bridges) cout << it.fi << " " << it.se << "\n";
   if(n > 100 && p > 100)return;
    for(int i = 0; i < m; i++){
        if(mp[{min(edges[i].fi, edges[i].se), max(edges[i].fi, edges[i].se)}].size() > 1){
                //cout<<"OK\n";
       // cout << i << " " << mp[{min(edges[i].fi, edges[i].se), max(edges[i].fi, edges[i].se)}][0] << "\n";
            ans[i] = 'B';
            if(i == mp[{min(edges[i].fi, edges[i].se), max(edges[i].fi, edges[i].se)}][0]){
                    //cout << "OK\n";
                Adj2[edges[i].fi].pb(edges[i].se);
                Adj2[edges[i].se].pb(edges[i].fi);
            }
            continue;
        }
        if(bridges.find({min(edges[i].fi, edges[i].se), max(edges[i].fi, edges[i].se)}) == bridges.end()){
            ans[i] = 'B';
            Adj2[edges[i].fi].pb(edges[i].se);
            Adj2[edges[i].se].pb(edges[i].fi);
           // cout << edges[i].fi << " " << edges[i].se << "\n";
            continue;
        }
        //cout << i << "\n";
    }
    for(int i = 1; i <= n; i++){
        if(!comp[i]){
            cnt_comp++;
            dfs2(i);
        }
    }
    //for(int i = 1; i <= n; i++) cout << i << " " << low[i] << " " << ti[i] << " " << comp[i] << "\n";
   // return;
    for(int i = 0; i < m; i++){
        if(ans[i] != 'B'){
            assert(comp[edges[i].fi] != comp[edges[i].se]);
            //cout << edges[i].fi << " " << edges[i].se << "\n";
            //cout << comp[edges[i].fi] << " " << comp[edges[i].se] << "\n";
           // Adj3[comp[edges[i].fi]].pb({comp[edges[i].se], i});
        //    Adj3[comp[edges[i].se]].pb({comp[edges[i].fi], i});
            mp2[{min(comp[edges[i].fi], comp[edges[i].se]), max(comp[edges[i].fi], comp[edges[i].se])}].pb(i);
        }
    }
    for(auto it : mp2){
        if(it.se.size() > 1){
            for(auto temp : mp2[it.fi]){
                ans[temp] = 'B';
            }
        }
        int x = mp2[it.fi][0];
        Adj3[it.fi.fi].pb({it.fi.se, x});
        Adj3[it.fi.se].pb({it.fi.fi, x});
        //cout << it.fi.fi << " " << it.fi.se << " " << x << "\n";
    }
    //return;
    for(int i = 1; i <= cnt_comp; i++) if(!d[i]) dfs3(i, i);
    //cout << "OK\n";
    cin >> p;
    for(int i = 1; i <= p; i++){
        int x, y;
        cin >> x >> y;
        if(comp[x] == comp[y]) continue;
        int z = lca(comp[x], comp[y]);
        //cout << comp[x] << " " << comp[y] << " " << z << "\n";
        que[comp[x]].pb({d[z], 0});
        que[comp[y]].pb({d[z], 1});
    }
    for(int i = 1; i <= cnt_comp; i++){
        sz[i] = 1, rt[i] = i;
    }
    for(int i = 1; i <= cnt_comp; i++){
        if(!d[i]){
          //  cout << i << "\n";
            dfs4(i, i);
        }
    }
    for(int i = 0; i < m; i++){
        if(ans[i] != 'B'){
            if(answ[i] == comp[edges[i].fi]) ans[i] = 'R';
            else ans[i] = 'L';
        }
        //cout << i << " " << edges[i].fi << " " << edges[i].se << "\n";
        cout << ans[i] << "";
    }
    string s;
    cin >> s;
    for(int i = 0; i < m; i++){
        /*
        if(i != 771){
            //ii temp1 = {329, 139}, temp2 = {137, 329};
            //assert(edges[i] != temp1);
            //assert(edges[i] != temp2);
        }*/
        //if(ans[i] != s[i]) cout << i << " " << s[i] << " " << ans[i] << "\n";
    }
}

signed main(){
  //  freopen("temp.inp", "r", stdin);
    //freopen("temp.out", "w", stdout);
    ios_base::sync_with_stdio(0);
    process();
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 42616 KB Output is correct
2 Correct 25 ms 42648 KB Output is correct
3 Correct 25 ms 42828 KB Output is correct
4 Correct 24 ms 43220 KB Output is correct
5 Correct 24 ms 43296 KB Output is correct
6 Correct 23 ms 42708 KB Output is correct
7 Correct 24 ms 43220 KB Output is correct
8 Correct 32 ms 43200 KB Output is correct
9 Correct 22 ms 42848 KB Output is correct
10 Correct 23 ms 42828 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 42616 KB Output is correct
2 Correct 25 ms 42648 KB Output is correct
3 Correct 25 ms 42828 KB Output is correct
4 Correct 24 ms 43220 KB Output is correct
5 Correct 24 ms 43296 KB Output is correct
6 Correct 23 ms 42708 KB Output is correct
7 Correct 24 ms 43220 KB Output is correct
8 Correct 32 ms 43200 KB Output is correct
9 Correct 22 ms 42848 KB Output is correct
10 Correct 23 ms 42828 KB Output is correct
11 Correct 295 ms 63092 KB Output is correct
12 Correct 278 ms 64572 KB Output is correct
13 Correct 316 ms 67744 KB Output is correct
14 Correct 354 ms 76604 KB Output is correct
15 Correct 369 ms 80352 KB Output is correct
16 Correct 493 ms 102776 KB Output is correct
17 Correct 477 ms 105896 KB Output is correct
18 Correct 493 ms 103336 KB Output is correct
19 Correct 466 ms 107804 KB Output is correct
20 Correct 271 ms 65316 KB Output is correct
21 Correct 217 ms 64392 KB Output is correct

Subtask #3
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 42616 KB Output is correct
2 Correct 25 ms 42648 KB Output is correct
3 Correct 25 ms 42828 KB Output is correct
4 Correct 24 ms 43220 KB Output is correct
5 Correct 24 ms 43296 KB Output is correct
6 Correct 23 ms 42708 KB Output is correct
7 Correct 24 ms 43220 KB Output is correct
8 Correct 32 ms 43200 KB Output is correct
9 Correct 22 ms 42848 KB Output is correct
10 Correct 23 ms 42828 KB Output is correct
11 Correct 295 ms 63092 KB Output is correct
12 Correct 278 ms 64572 KB Output is correct
13 Correct 316 ms 67744 KB Output is correct
14 Correct 354 ms 76604 KB Output is correct
15 Correct 369 ms 80352 KB Output is correct
16 Correct 493 ms 102776 KB Output is correct
17 Correct 477 ms 105896 KB Output is correct
18 Correct 493 ms 103336 KB Output is correct
19 Correct 466 ms 107804 KB Output is correct
20 Correct 271 ms 65316 KB Output is correct
21 Correct 217 ms 64392 KB Output is correct
22 Execution timed out 3079 ms 115344 KB Time limit exceeded
23 Halted 0 ms 0 KB -