Submission #230364

#	Time	Username	Problem	Language	Result	Execution time	Memory
230364		parsa_mobed	Pipes (CEOI15_pipes)	C++14	0 / 100	4101 ms	15224 KiB

pipes

#include <bits/stdc++.h>


using namespace std;
const int N = 1e5 + 1, M = 6e6, LOG = 17;
int h[N], val[N], par[N][LOG];
bitset <M> E;
vector <int> g[N];

int getpar(int v, int height) {
    for (int i = 0; height; height>>=1, i++) if (height&1) v = par[v][i];
    return v;
}
int LCA(int u, int v) {
    if (h[u] > h[v]) swap(u, v);
    v = getpar(v, h[v] - h[u]);
    if (u == v) return v;
    for (int i = LOG - 1; i >= 0; i--) if (par[v][i] != par[u][i]) v = par[v][i], u = par[u][i];
    return par[v][0];
}
void init(int n) {for (int i = 1; i <= n; i++) par[i][0] = i; return ;}
int getroot(int u) {return par[u][0] = (par[u][0] == u ? u : getroot(par[u][0]));}
void Union(int u, int v, int id) {
    int ru = getroot(u), rv = getroot(v);
    if (ru == rv) {E[id] = 0; return ;}
    par[ru][0] = rv, g[u].push_back(v), g[v].push_back(u);
}
void dfs(int v) {
    for (int i = 1; i < LOG; i++) par[v][i] = par[par[v][i - 1]][i - 1];
    for (int u : g[v]) if (!h[u]) h[u] = h[v] + 1, par[u][0] = v, dfs(u);
}
void Solve(int v) {
    for (int u : g[v]) if (!h[u]) h[u] = 1, Solve(u), val[v] += val[u];
    if (par[v][0] && val[v]) cout << v << " " << par[v][0] << "\n";
}
int main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int n, m; cin >> n >> m, init(n), E.set();
    for (int i = 0; i < m; i++) {int u, v; cin >> u >> v, Union(u, v, i);}
    for (int i = 1; i <= n; i++) if (!h[i]) par[i][0] = i, h[i] = 1, dfs(i);
    memset(h, 0, sizeof h), cin.seekg(0);
    cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int u, v; cin >> u >> v;
        if (!E[i]) val[u]++, val[v]++, val[LCA(u, v)] -= 2;
    }
    for (int i = 1; i <= n; i++) if (!h[i]) Solve(i);
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10