QOJ.ac
QOJ
ID | Submission ID | Problem | Hacker | Owner | Result | Submit time | Judge time |
---|---|---|---|---|---|---|---|
#543 | #188567 | #7222. The Great Hunt | ricky_lin | ucup-team004 | Failed. | 2024-02-21 15:39:57 | 2024-02-21 15:39:58 |
Details
Extra Test:
Accepted
time: 472ms
memory: 22640kb
input:
9984 2 1 3 2 4 3 5 4 6 5 7 6 8 7 9 8 10 9 11 10 12 11 13 12 14 13 15 14 16 15 17 16 18 17 19 18 20 19 21 20 22 21 23 22 24 23 25 24 26 25 27 26 28 27 29 28 30 29 31 30 32 31 33 32 34 33 35 34 36 35 37 36 38 37 39 38 40 39 41 40 42 41 43 42 44 43 45 44 46 45 47 46 48 47 49 48 50 49 51 50 52 51 53 52 ...
output:
No
result:
ok
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#188567 | #7222. The Great Hunt | ucup-team004 | AC ✓ | 653ms | 26292kb | C++20 | 4.7kb | 2023-09-26 01:09:03 | 2023-09-26 01:09:03 |
answer
#include <bits/stdc++.h>
using i64 = long long;
constexpr int V = 2E5;
struct Edge {
int to;
int cap;
};
std::vector<Edge> e;
std::vector<int> adj[V];
void addEdge(int u, int v, int cap) {
adj[u].push_back(e.size());
e.push_back({v, cap});
adj[v].push_back(e.size());
e.push_back({u, 0});
}
constexpr int inf = 1E9;
int h[V];
int tot = 0;
int cur[V];
bool bfs(int s, int t) {
std::fill(h, h + tot, -1);
std::queue<int> q;
q.push(s);
h[s] = 0;
while (!q.empty()) {
int x = q.front();
q.pop();
for (auto i : adj[x]) {
auto [y, cap] = e[i];
if (cap > 0 && h[y] == -1) {
h[y] = h[x] + 1;
q.push(y);
}
}
}
return h[t] != -1;
}
int dfs(int x, int t, int f) {
if (x == t) {
return f;
}
int res = 0;
for (auto &i = cur[x]; i < adj[x].size(); i++) {
int j = adj[x][i];
auto [y, cap] = e[j];
if (cap > 0 && h[y] == h[x] + 1) {
int a = dfs(y, t, std::min(cap, f));
f -= a;
res += a;
e[j].cap -= a;
e[j ^ 1].cap += a;
if (f == 0) {
break;
}
}
}
return res;
}
int flow(int s, int t) {
int ans = 0;
while (bfs(s, t)) {
std::fill(cur, cur + tot, 0);
ans += dfs(s, t, inf);
}
return ans;
}
constexpr int N = 1E4;
int f[N];
int g[N];
int find(int x) {
if (f[f[x]] == f[x]) {
return f[x];
}
int y = find(f[x]);
int u = tot++;
if (g[x] != -1) {
addEdge(u, g[x], inf);
}
if (g[f[x]] != -1) {
addEdge(u, g[f[x]], inf);
}
f[x] = y;
g[x] = u;
return y;
}
void merge(int x, int y) {
x = find(x);
y = find(y);
f[y] = x;
}
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int n;
std::cin >> n;
std::iota(f, f + n, 0);
std::fill(g, g + n, -1);
std::vector<std::vector<int>> adj(n);
for (int i = 1; i < n; i++) {
int u, v;
std::cin >> u >> v;
u--, v--;
adj[u].push_back(v);
adj[v].push_back(u);
}
tot = 2 * n + 2;
int s = 2 * n, t = 2 * n + 1;
for (int i = 0; i < n; i++) {
addEdge(s, n + i, 1);
addEdge(i, t, 1);
}
const int logn = std::__lg(n);
std::vector p(logn + 1, std::vector<int>(n, -1));
std::vector id(logn + 1, std::vector<int>(n, -1));
std::vector<int> dep(n);
auto dfs = [&](auto self, int x) -> void {
id[0][x] = x;
for (int i = 0; (2 << i) <= dep[x]; i++) {
p[i + 1][x] = p[i][p[i][x]];
id[i + 1][x] = tot++;
addEdge(id[i + 1][x], id[i][x], inf);
addEdge(id[i + 1][x], id[i][p[i][x]], inf);
}
for (auto y : adj[x]) {
if (y == p[0][x]) {
continue;
}
dep[y] = dep[x] + 1;
p[0][y] = x;
self(self, y);
}
};
dfs(dfs, 0);
for (int i = 0; i < n; i++) {
int u, v;
std::cin >> u >> v;
u--, v--;
if (dep[u] < dep[v]) {
std::swap(u, v);
}
for (int j = logn; j >= 0; j--) {
if (dep[u] - (1 << j) >= dep[v]) {
addEdge(n + i, id[j][u], 1);
u = p[j][u];
}
}
for (int j = logn; j >= 0; j--) {
if (p[j][u] != p[j][v]) {
addEdge(n + i, id[j][u], 1);
addEdge(n + i, id[j][v], 1);
u = p[j][u];
v = p[j][v];
}
}
if (u != v) {
addEdge(n + i, u, 1);
addEdge(n + i, v, 1);
u = p[0][u], v = p[0][v];
}
addEdge(n + i, u, 1);
}
int ans = flow(s, t);
if (ans < n) {
std::cout << "No\n";
return 0;
}
std::cout << "Yes\n";
std::vector<int> a(n);
std::fill(cur, cur + tot, 0);
auto match = [&](auto self, int x) {
if (x < n) {
return x;
}
for (auto &i = cur[x]; i < ::adj[x].size(); i++) {
int j = ::adj[x][i];
auto [y, cap] = e[j];
if (j % 2 == 0 && e[j ^ 1].cap > 0) {
e[j ^ 1].cap--;
return self(self, y);
}
}
assert(false);
};
for (int i = 0; i < n; i++) {
a[i] = match(match, n + i);
std::cout << a[i] + 1 << " \n"[i == n - 1];
}
return 0;
}