oj.uz

Submission #321781

# Submission time Handle Problem Language Result Execution time Memory
321781 2020-11-13T11:05:05 Z Karen124 One-Way Streets (CEOI17_oneway) C++14
100 / 100
 218 ms 17384 KB 
#pragma GCC optimize("O2")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
     
using namespace std;
     
#define ll long long int 
#define F first
#define S second
#define pb push_back
 
const ll N = 1e5 + 10;
const ll LOG = 20;
const ll MOD = 1e9 + 7;
const ll INF = 1e9 + 10;
struct Edge{
    int u, v;
} e[N];
int n, m, p, a[N], b[N];
int h[N], mn[N];
int pr[N], sz[N];
int rev[N], ps[N];
vector < pair <int, int> > adj[N];
vector <int>  E;
bool mrk[N], is[N];
void dfs(int v, int i){
    mrk[v] = 1; mn[v] = h[v];
    for (auto it : adj[v]){
        int u = it.F, j = it.S;
        if (!mrk[u]){
            h[u] = h[v] + 1;
            dfs(u, j);
            mn[v] = min(mn[u], mn[v]);
        }
        else if (i != j){
            mn[v] = min(mn[v], h[u]);   
        }
    }
    if(i && mn[v] == h[v]){
        E.pb(i);
        is[i] = 1;
    }
    return;
}
int find(int v){
    if (pr[v] == v) return v;
    return (pr[v] = find(pr[v]));
}
void merge(int u, int v){
    u = find(u); v = find(v);
    if (u == v) return;
    if (sz[v] < sz[u]) swap(u, v);
    pr[u] = v;
    sz[v] += sz[u];
    return;
}
void dfs_dead(int v, int i){
    mrk[v] = 1;
    for (auto it : adj[v]){
        int u = it.F, j = it.S;
        if (mrk[u]) continue;
        dfs_dead(u, j);
        ps[v] += ps[u];
    }
    if (i && ps[v]){
        rev[i] = 1;
        rev[i] += (0 < ps[v] && find(e[i].u) == v);    
        rev[i] += (ps[v] < 0 && find(e[i].v) == v);
    }
    return;
}
int main() {
    cin >> n >> m;
    for (int i = 1; i <= m; i++){
        cin >> e[i].u >> e[i].v;
        adj[e[i].u].pb({e[i].v, i});
        adj[e[i].v].pb({e[i].u, i});
    }
    for (int i = 1; i <= n; i++){
        if (!mrk[i]){
            dfs(i, 0);
        }
        sz[i] = 1; pr[i] = i;
    }
    cin >> p;
    for (int i = 1; i <= p; i++){
        cin >> a[i] >> b[i];
    }
    for (int i = 1; i <= m; i++){
        if (!is[i]){
            merge(e[i].u, e[i].v);
        }
    }
    for (int i = 1; i <= n; i++) adj[i].clear();
    for (int i : E){
        adj[find(e[i].u)].pb({find(e[i].v), i});
        adj[find(e[i].v)].pb({find(e[i].u), i});
    }
    for (int i = 1; i <= p; i++){
        if (find(a[i]) == find(b[i])) continue;
        ps[find(a[i])]--; ps[find(b[i])]++; 
    }
    fill(mrk, mrk + n + 1, 0);
    for (int i = 1; i <= n; i++){
        if (!mrk[find(i)]){
            dfs_dead(find(i), 0);
        }
    }
    for (int i = 1; i <= m; i++){
        if (rev[i] == 1) cout << "R";
        else if (rev[i] == 2) cout << "L";
        else cout << "B";
    }
    cout << '\n';
    return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2692 KB Output is correct
2 Correct 3 ms 2668 KB Output is correct
3 Correct 4 ms 2796 KB Output is correct
4 Correct 4 ms 2796 KB Output is correct
5 Correct 3 ms 2796 KB Output is correct
6 Correct 3 ms 2796 KB Output is correct
7 Correct 4 ms 2796 KB Output is correct
8 Correct 4 ms 2796 KB Output is correct
9 Correct 4 ms 2796 KB Output is correct
10 Correct 4 ms 2944 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2692 KB Output is correct
2 Correct 3 ms 2668 KB Output is correct
3 Correct 4 ms 2796 KB Output is correct
4 Correct 4 ms 2796 KB Output is correct
5 Correct 3 ms 2796 KB Output is correct
6 Correct 3 ms 2796 KB Output is correct
7 Correct 4 ms 2796 KB Output is correct
8 Correct 4 ms 2796 KB Output is correct
9 Correct 4 ms 2796 KB Output is correct
10 Correct 4 ms 2944 KB Output is correct
11 Correct 84 ms 8812 KB Output is correct
12 Correct 92 ms 10092 KB Output is correct
13 Correct 114 ms 11500 KB Output is correct
14 Correct 123 ms 12908 KB Output is correct
15 Correct 137 ms 13032 KB Output is correct
16 Correct 134 ms 10852 KB Output is correct
17 Correct 126 ms 12976 KB Output is correct
18 Correct 138 ms 11120 KB Output is correct
19 Correct 112 ms 14312 KB Output is correct
20 Correct 95 ms 9580 KB Output is correct
21 Correct 87 ms 9836 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2692 KB Output is correct
2 Correct 3 ms 2668 KB Output is correct
3 Correct 4 ms 2796 KB Output is correct
4 Correct 4 ms 2796 KB Output is correct
5 Correct 3 ms 2796 KB Output is correct
6 Correct 3 ms 2796 KB Output is correct
7 Correct 4 ms 2796 KB Output is correct
8 Correct 4 ms 2796 KB Output is correct
9 Correct 4 ms 2796 KB Output is correct
10 Correct 4 ms 2944 KB Output is correct
11 Correct 84 ms 8812 KB Output is correct
12 Correct 92 ms 10092 KB Output is correct
13 Correct 114 ms 11500 KB Output is correct
14 Correct 123 ms 12908 KB Output is correct
15 Correct 137 ms 13032 KB Output is correct
16 Correct 134 ms 10852 KB Output is correct
17 Correct 126 ms 12976 KB Output is correct
18 Correct 138 ms 11120 KB Output is correct
19 Correct 112 ms 14312 KB Output is correct
20 Correct 95 ms 9580 KB Output is correct
21 Correct 87 ms 9836 KB Output is correct
22 Correct 177 ms 13788 KB Output is correct
23 Correct 193 ms 11908 KB Output is correct
24 Correct 218 ms 12004 KB Output is correct
25 Correct 185 ms 17384 KB Output is correct
26 Correct 196 ms 13400 KB Output is correct
27 Correct 182 ms 12004 KB Output is correct
28 Correct 87 ms 7276 KB Output is correct
29 Correct 151 ms 9852 KB Output is correct
30 Correct 157 ms 10476 KB Output is correct
31 Correct 164 ms 10348 KB Output is correct
32 Correct 174 ms 12892 KB Output is correct