oj.uz

Submission #1005301

# Submission time Handle Problem Language Result Execution time Memory
1005301 2024-06-22T10:06:50 Z Essa2006 One-Way Streets (CEOI17_oneway) C++14
100 / 100
 517 ms 66772 KB 
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
#define FF first
#define SS second
#define all(a) a.begin(), a.end()
#define mod (ll)(1000000007)

const int inf = 1e9, lg = 20;
int n, m, p, time_;
vector<int> Vis, up, dpth, upx, upy, dis, fin, U, V;
vector<vector<int>> A, X, Y, Lca;
map<array<int, 2>, int> dir, has, go;

void pre() {
    Vis.resize(n + 1), up.resize(n + 1, inf), dpth.resize(n + 1, inf), upx.resize(n + 1, inf), upy.resize(n + 1, inf), dis.resize(n + 1), fin.resize(n + 1), U.resize(m), V.resize(m);
    A.resize(n + 1), X.resize(n + 1), Y.resize(n + 1), Lca.resize(n + 1, vector<int>(lg + 1));
}

int lca(int u, int v) {
    if (dpth[u] > dpth[v]) {
        swap(u, v);
    }

    // u

    // v

    for (int i = lg; i >= 0; i--) {
        if (dpth[Lca[v][i]] >= dpth[u]) {
            v = Lca[v][i];
        }
    }

    for (int i = lg; i >= 0; i--) {
        if (Lca[v][i] != Lca[u][i]) {
            u = Lca[u][i], v = Lca[v][i];
        }
    }
    if (u != v) {
        u = Lca[u][0];
    }
    return u;
}

void dfs(int u, int p = -1) {
    Vis[u] = 1;
    up[u] = dpth[u];
    for (auto v : A[u]) {
        if (v == p) {
            continue;
        }
        if (!Vis[v]) {
            dpth[v] = dpth[u] + 1;
            dfs(v, u);
            upx[u] = min(upx[u], upx[v]);
            upy[u] = min(upy[u], upy[v]);
        }
        up[u] = min(up[u], up[v]);
    }

    for (int i = 0; i < X[u].size(); i++) {
        upx[u] = min(upx[u], dpth[lca(u, X[u][i])]);
    }
    for (int i = 0; i < Y[u].size(); i++) {
        upy[u] = min(upy[u], dpth[lca(u, Y[u][i])]);
    }

    if (up[u] == dpth[u] && has[{u, p}] == 1) {
        assert(max(upx[u], upy[u]) >= dpth[u]);
        if (upy[u] < dpth[u]) {
            go[{u, p}] = 1;
        }
        else if (upx[u] < dpth[u]){
            go[{p, u}] = 1;
        }
    }
}

void calc(int u, int p = -1) {
    dis[u] = ++time_;
    Lca[u][0] = (p == -1 ? u : p);
    for (int i = 1; i <= lg; i++) {
        Lca[u][i] = Lca[Lca[u][i - 1]][i - 1];
    }
    for (auto v : A[u]) {
        if (!dis[v]) {
            dpth[v] = dpth[u] + 1;
            calc(v, u);
        }
    }
    fin[u] = ++time_;
}

int main() {
    ios_base::sync_with_stdio(0);cin.tie(0);

    cin >> n >> m;
    pre();

    for (int i = 0; i < m; i++){
        int u, v;
        cin >> u >> v;

        A[u].push_back(v);
        A[v].push_back(u);
        dir[{u, v}] = 1;
        has[{u, v}]++;
        has[{v, u}]++;

        U[i] = u, V[i] = v;
    }

    cin >> p;
    for (int i = 0 ; i < p; i++) {
        int x, y;
        cin >> x >> y;

        X[y].push_back(x);
        Y[x].push_back(y);
    }

    for (int i = 1; i <= n; i++) {
        if (Vis[i]) {
            continue;
        }
        dpth[i] = 0;
        calc(i);
        dfs(i);
    }

    for (int i = 0; i < m; i++) {
        int u = U[i], v = V[i];
        if (!(go[{u, v}] || go[{v, u}]) || u == v || has[{u, v}] != 1) {
            cout << 'B';
            continue;
        }
        if (go[{u, v}]) {
            cout << 'R';
            continue;
        }
        cout << 'L';
    }
}

Compilation message

oneway.cpp: In function 'void dfs(int, int)':
oneway.cpp:63:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |     for (int i = 0; i < X[u].size(); i++) {
      |                     ~~^~~~~~~~~~~~~
oneway.cpp:66:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   66 |     for (int i = 0; i < Y[u].size(); i++) {
      |                     ~~^~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 2 ms 860 KB Output is correct
4 Correct 2 ms 860 KB Output is correct
5 Correct 2 ms 860 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 2 ms 928 KB Output is correct
9 Correct 2 ms 856 KB Output is correct
10 Correct 1 ms 860 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 2 ms 860 KB Output is correct
4 Correct 2 ms 860 KB Output is correct
5 Correct 2 ms 860 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 2 ms 928 KB Output is correct
9 Correct 2 ms 856 KB Output is correct
10 Correct 1 ms 860 KB Output is correct
11 Correct 237 ms 41040 KB Output is correct
12 Correct 251 ms 44884 KB Output is correct
13 Correct 238 ms 50512 KB Output is correct
14 Correct 250 ms 57680 KB Output is correct
15 Correct 278 ms 60064 KB Output is correct
16 Correct 288 ms 57936 KB Output is correct
17 Correct 304 ms 59816 KB Output is correct
18 Correct 294 ms 57972 KB Output is correct
19 Correct 287 ms 61780 KB Output is correct
20 Correct 213 ms 48212 KB Output is correct
21 Correct 184 ms 46416 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 2 ms 860 KB Output is correct
4 Correct 2 ms 860 KB Output is correct
5 Correct 2 ms 860 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 2 ms 928 KB Output is correct
9 Correct 2 ms 856 KB Output is correct
10 Correct 1 ms 860 KB Output is correct
11 Correct 237 ms 41040 KB Output is correct
12 Correct 251 ms 44884 KB Output is correct
13 Correct 238 ms 50512 KB Output is correct
14 Correct 250 ms 57680 KB Output is correct
15 Correct 278 ms 60064 KB Output is correct
16 Correct 288 ms 57936 KB Output is correct
17 Correct 304 ms 59816 KB Output is correct
18 Correct 294 ms 57972 KB Output is correct
19 Correct 287 ms 61780 KB Output is correct
20 Correct 213 ms 48212 KB Output is correct
21 Correct 184 ms 46416 KB Output is correct
22 Correct 499 ms 61432 KB Output is correct
23 Correct 472 ms 58452 KB Output is correct
24 Correct 506 ms 58416 KB Output is correct
25 Correct 517 ms 66772 KB Output is correct
26 Correct 501 ms 60544 KB Output is correct
27 Correct 475 ms 58704 KB Output is correct
28 Correct 96 ms 5716 KB Output is correct
29 Correct 328 ms 50520 KB Output is correct
30 Correct 320 ms 50772 KB Output is correct
31 Correct 317 ms 51364 KB Output is correct
32 Correct 357 ms 50004 KB Output is correct