oj.uz

Submission #563744

# Submission time Handle Problem Language Result Execution time Memory
563744 2022-05-18T05:02:59 Z minhcool One-Way Streets (CEOI17_oneway) C++17
60 / 100
 3000 ms 115120 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);
        }
    }
    if(n > 100 && p > 100)return;
    for(int i = 1; i <= n; i++) if(!ti[i]) dfs(i, i);
    //for(auto it : bridges) cout << it.fi << " " << it.se << "\n";

    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 26 ms 42572 KB Output is correct
2 Correct 24 ms 42612 KB Output is correct
3 Correct 23 ms 42888 KB Output is correct
4 Correct 25 ms 43164 KB Output is correct
5 Correct 27 ms 43256 KB Output is correct
6 Correct 24 ms 42768 KB Output is correct
7 Correct 26 ms 43224 KB Output is correct
8 Correct 26 ms 43268 KB Output is correct
9 Correct 24 ms 42780 KB Output is correct
10 Correct 28 ms 42956 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 42572 KB Output is correct
2 Correct 24 ms 42612 KB Output is correct
3 Correct 23 ms 42888 KB Output is correct
4 Correct 25 ms 43164 KB Output is correct
5 Correct 27 ms 43256 KB Output is correct
6 Correct 24 ms 42768 KB Output is correct
7 Correct 26 ms 43224 KB Output is correct
8 Correct 26 ms 43268 KB Output is correct
9 Correct 24 ms 42780 KB Output is correct
10 Correct 28 ms 42956 KB Output is correct
11 Correct 259 ms 63048 KB Output is correct
12 Correct 280 ms 64608 KB Output is correct
13 Correct 314 ms 67856 KB Output is correct
14 Correct 358 ms 76552 KB Output is correct
15 Correct 370 ms 80252 KB Output is correct
16 Correct 490 ms 102708 KB Output is correct
17 Correct 479 ms 105892 KB Output is correct
18 Correct 532 ms 103220 KB Output is correct
19 Correct 498 ms 107760 KB Output is correct
20 Correct 247 ms 65296 KB Output is correct
21 Correct 240 ms 64448 KB Output is correct

Subtask #3
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 42572 KB Output is correct
2 Correct 24 ms 42612 KB Output is correct
3 Correct 23 ms 42888 KB Output is correct
4 Correct 25 ms 43164 KB Output is correct
5 Correct 27 ms 43256 KB Output is correct
6 Correct 24 ms 42768 KB Output is correct
7 Correct 26 ms 43224 KB Output is correct
8 Correct 26 ms 43268 KB Output is correct
9 Correct 24 ms 42780 KB Output is correct
10 Correct 28 ms 42956 KB Output is correct
11 Correct 259 ms 63048 KB Output is correct
12 Correct 280 ms 64608 KB Output is correct
13 Correct 314 ms 67856 KB Output is correct
14 Correct 358 ms 76552 KB Output is correct
15 Correct 370 ms 80252 KB Output is correct
16 Correct 490 ms 102708 KB Output is correct
17 Correct 479 ms 105892 KB Output is correct
18 Correct 532 ms 103220 KB Output is correct
19 Correct 498 ms 107760 KB Output is correct
20 Correct 247 ms 65296 KB Output is correct
21 Correct 240 ms 64448 KB Output is correct
22 Execution timed out 3085 ms 115120 KB Time limit exceeded
23 Halted 0 ms 0 KB -