| # | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1073000 | 2024-08-24T08:20:09 Z | Ignut | Stations (IOI20_stations) | C++17 | 0 ms | 0 KB |
// Ignut
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 1111;
vector<int> tree[N];
vector<int> order;
vector<int> dist;
void dfs(int v, int par, int d) {
order.push_back(v);
for (int to : tree[v])
if (to != par)
dfs(to, v);
}
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
order.clear();
for (int i = 0; i < n; i ++) {
tree[i].clear();
}
for (int i = 0; i < n - 1; i ++) {
tree[u[i]].push_back(v[i]);
tree[v[i]].push_back(u[i]);
}
vector<int> lbl(n);
for (int i = 0; i < n; i ++) {
vector<int> vec = {i + 1};
for (int to : tree[i]) {
order.clear();
dfs(to, i);
for (int val : order) vec.push_back(val + 1);
order.clear();
}
lbl[i] = 0;
for (int val : vec) lbl[i] = lbl[i] * 10 + val;
}
return lbl;
}
int find_next_station(int s, int t, vector<int> c) {
if (c.size() == 1) return c[0];
for (int val : c) if (val == t) return t;
}
static int max_label = 0;
static int r, n, k, q;
static std::vector<int> u, v, labels, answers;
static std::map<int, int> reverse_labels;
static std::vector<std::vector<int>> adjlist;
static int s, t, w;
static std::vector<int> c;
int main() {
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
assert(scanf("%d", &r) == 1);
for (int tc = 0; tc < r; tc++) {
assert(scanf("%d%d", &n, &k) == 2);
u.resize(n - 1);
v.resize(n - 1);
adjlist.clear();
adjlist.resize(n);
for (int i = 0; i < n - 1; i++) {
assert(scanf("%d%d", &u[i], &v[i]) == 2);
adjlist[u[i]].push_back(v[i]);
adjlist[v[i]].push_back(u[i]);
}
labels = label(n, k, u, v);
if ((int)labels.size() != n) {
printf("Number of labels not equal to %d\n", n);
exit(0);
}
reverse_labels.clear();
for (int i = 0; i < n; i++) {
if (labels[i] < 0 || labels[i] > k) {
printf("Label not in range 0 to %d\n", k);
exit(0);
}
if (reverse_labels.find(labels[i]) != reverse_labels.end()) {
printf("Labels not unique\n");
exit(0);
}
reverse_labels[labels[i]] = i;
if (labels[i] > max_label) {
max_label = labels[i];
}
}
assert(scanf("%d", &q) == 1);
for (int i = 0; i < q; i++) {
assert(scanf("%d%d%d", &s, &t, &w) == 3);
c.clear();
for (int v : adjlist[s]) {
c.push_back(labels[v]);
}
std::sort(c.begin(), c.end());
int answer = find_next_station(labels[s], labels[t], c);
if (!std::binary_search(c.begin(), c.end(), answer)) {
printf("Label %d returned by find_next_station not found in c\n", answer);
exit(0);
}
answers.push_back(reverse_labels[answer]);
}
}
printf("%d\n", max_label);
for (int index : answers) {
printf("%d\n", index);
}
exit(0);
}
/*
1
8 1000000
0 1
1 4
2 3
3 4
4 5
4 6
6 7
5
0 4 4
2 5 5
3 7 7
2 5 3
3 7 4
*/