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Submission #348575

# Submission time Handle Problem Language Result Execution time Memory
348575 2021-01-15T08:48:00 Z Nima_Naderi One-Way Streets (CEOI17_oneway) C++14
100 / 100
 156 ms 26204 KB 
///In the name of GOD
#pragma GCC optimize("O2")
#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
const ll MXN = 1e5 + 10;
const ll INF = 1e18;
ll n, m, q;
ll Par[MXN], Sz[MXN], Min[MXN], dis[MXN], num[MXN];
vector<pair<ll, ll>> adj[MXN], G[MXN], Edge;
bool vis[MXN], mark[MXN];
string ANS;
ll Find(ll x){
    return (Par[x] == x ? x : Par[x] = Find(Par[x]));
}
void Union(ll x, ll y){
    x = Find(x), y = Find(y);
    if(x == y) return;
    if(Sz[x] < Sz[y]) swap(x, y);
    Sz[x] += Sz[y], Par[y] = x;
}
void dfs(ll u, ll pid){
    vis[u] = 1, Min[u] = INF;
    for(auto Pr : adj[u]){
        ll v, id; tie(v, id) = Pr;
        if(id == pid) continue;
        if(vis[v]){
            Min[u] = min(Min[u], dis[v]);
            ANS[id] = 'B';
            continue;
        }
        dis[v] = dis[u] + 1;
        dfs(v, id);
        Min[u] = min(Min[u], Min[v]);
        if(Min[v] <= dis[u]) Union(u, v), ANS[id] = 'B';
    }
}
void DFS(ll u, ll par){
    mark[u] = 1;
    for(auto Pr : G[u]){
        ll v, id; tie(v, id) = Pr;
        if(v == par) continue;
        DFS(v, u);
        num[u] += num[v];
        if(num[v] == 0) ANS[id] = 'B';
        else{
            ll from = (num[v] > 0 ? v : u);
            ANS[id] = (from == Find(Edge[id - 1].first) ? 'R' : 'L');
        }
    }
}
int main(){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
    cin >> n >> m;
    ANS = "$";
    for(int i = 1; i <= n; i ++) Par[i] = i, Sz[i] = 1;
    for(int i = 1; i <= m; i ++){
        ll u, v; cin >> u >> v;
        adj[u].push_back({v, i});
        adj[v].push_back({u, i});
        Edge.push_back({u, v});
        ANS += "N";
    }
    for(int i = 1; i <= n; i ++){
        if(!vis[i]) dfs(i, 0);
    }
    for(int i = 0; i < m; i ++){
        ll u, v; tie(u, v) = Edge[i];
        u = Find(u), v = Find(v);
        if(u == v){
            assert(ANS[i + 1] == 'B');
            continue;
        }
        assert(ANS[i + 1] == 'N');
        G[u].push_back({v, i + 1});
        G[v].push_back({u, i + 1});
    }
    cin >> q;
    while(q --){
        ll u, v; cin >> u >> v;
        u = Find(u), v = Find(v);
        num[u] ++, num[v] --;
    }
    for(int i = 1; i <= n; i ++){
        if(Par[i] != i) continue;
        if(!mark[i]) DFS(i, 0);
    }
    for(int i = 1; i <= m; i ++) assert(ANS[i] != 'N');
    cout << ANS.substr(1, m) << '\n';
    return 0;
}
/*!
    HE'S AN INSTIGATOR,
    ENEMY ELIMINATOR,
    AND WHEN HE KNOCKS YOU BETTER
    YOU BETTER LET HIM IN.
*/
//! N.N

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5228 KB Output is correct
4 Correct 4 ms 5228 KB Output is correct
5 Correct 5 ms 5228 KB Output is correct
6 Correct 4 ms 5228 KB Output is correct
7 Correct 4 ms 5228 KB Output is correct
8 Correct 4 ms 5228 KB Output is correct
9 Correct 4 ms 5228 KB Output is correct
10 Correct 4 ms 5228 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5228 KB Output is correct
4 Correct 4 ms 5228 KB Output is correct
5 Correct 5 ms 5228 KB Output is correct
6 Correct 4 ms 5228 KB Output is correct
7 Correct 4 ms 5228 KB Output is correct
8 Correct 4 ms 5228 KB Output is correct
9 Correct 4 ms 5228 KB Output is correct
10 Correct 4 ms 5228 KB Output is correct
11 Correct 50 ms 14044 KB Output is correct
12 Correct 55 ms 15196 KB Output is correct
13 Correct 69 ms 16988 KB Output is correct
14 Correct 88 ms 18780 KB Output is correct
15 Correct 91 ms 19548 KB Output is correct
16 Correct 110 ms 21596 KB Output is correct
17 Correct 87 ms 23132 KB Output is correct
18 Correct 106 ms 21596 KB Output is correct
19 Correct 82 ms 24156 KB Output is correct
20 Correct 56 ms 14812 KB Output is correct
21 Correct 51 ms 14944 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5228 KB Output is correct
4 Correct 4 ms 5228 KB Output is correct
5 Correct 5 ms 5228 KB Output is correct
6 Correct 4 ms 5228 KB Output is correct
7 Correct 4 ms 5228 KB Output is correct
8 Correct 4 ms 5228 KB Output is correct
9 Correct 4 ms 5228 KB Output is correct
10 Correct 4 ms 5228 KB Output is correct
11 Correct 50 ms 14044 KB Output is correct
12 Correct 55 ms 15196 KB Output is correct
13 Correct 69 ms 16988 KB Output is correct
14 Correct 88 ms 18780 KB Output is correct
15 Correct 91 ms 19548 KB Output is correct
16 Correct 110 ms 21596 KB Output is correct
17 Correct 87 ms 23132 KB Output is correct
18 Correct 106 ms 21596 KB Output is correct
19 Correct 82 ms 24156 KB Output is correct
20 Correct 56 ms 14812 KB Output is correct
21 Correct 51 ms 14944 KB Output is correct
22 Correct 108 ms 23096 KB Output is correct
23 Correct 116 ms 21520 KB Output is correct
24 Correct 156 ms 21596 KB Output is correct
25 Correct 104 ms 26204 KB Output is correct
26 Correct 118 ms 22620 KB Output is correct
27 Correct 111 ms 21596 KB Output is correct
28 Correct 40 ms 11356 KB Output is correct
29 Correct 75 ms 14428 KB Output is correct
30 Correct 74 ms 14820 KB Output is correct
31 Correct 78 ms 14940 KB Output is correct
32 Correct 83 ms 18964 KB Output is correct