| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 971529 | fzyzzz_z | Tropical Garden (IOI11_garden) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "garden.h"
#include "gardenlib.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int mxn = 150005;
int g[2 * mxn], p[2 * mxn], vis[2 * mxn], c1[2 * mxn], c2[2 * mxn];
vector<int> r[2 * mxn];
void dfs_find(int x) {
if (vis[x]) return;
vis[x] = 1;
for (auto u: r[x]) {
dfs_find(u);
}
dfs_find(g[x]);
}
void dfs_c1(int x, int d) {
c1[d]++;
for (auto u: r[x]) {
dfs_c1(u, d + 1);
}
}
void dfs_c2(int x, int d, int f) {
c2[d]++;
for (auto u: r[x]) {
if (u != f) {
dfs_c2(u, d + 1, f);
}
}
}
void count_routes(int N, int M, int P, int R[][2], int Q, int G[]) {
vector<vector<int>> adj(N);
map<pair<int, int>, int> to;
vector<int> c;
for (int i = 0; i < M; ++i) {
int x = R[i][0], y = R[i][1];
to[{x, y}] = 2 * i;
to[{y, x}] = 2 * i + 1;
adj[x].push_back(y);
adj[y].push_back(x);
if (x == P) c.push_back(2 * i + 1);
if (y == P) c.push_back(2 * i);
}
for (int x = 0; x < N; ++x) {
for (int i = 1; i < adj[x].size(); ++i) {
g[to[{adj[x][i], x}]] = to[{x, adj[x][0]}];
}
g[to[{adj[x][0], x}]] = to[{x, adj[x][min(adj[x].size(), 2) - 1]}];
}
for (int x = 0; x < 2 * M; ++x) {
vis[x] = c1[x] = c2[x] = p[x] = 0;
}
for (int x = 0; x < 2 * M; ++x) {
r[g[x]].push_back(x);
p[g[x]]++;
}
dfs_find(c[0]);
for (auto x: c) assert(vis[x]);
queue<int> q;
for (int i = 0; i < 2 * M; ++i) {
if (vis[i] && p[i] == 0) {
q.push(i);
}
}
while (q.size()) {
auto x = q.front();
assert(vis[x]);
q.pop();
p[g[x]]--;
if (p[g[x]] == 0) {
q.push(g[x]);
}
}
for (int x = 0; x < 2 * M; ++x) if (vis[x]) assert(p[x] == 1 || p[x] == 0);
int co = 0;
for (auto x: c) if (p[x]) co++;
assert(co == 2);
for (auto x: c) {
if (p[x] == 0) {
dfs_c1(x, 0);
} else {
dfs_c2(x, 0, g[x]);
}
}
int clen = 0;
for (int i = 0; i < 2 * M; ++i) {
if (vis[i] && p[i]) clen++;
}
for (int i = 0; i < 2 * M; ++i) {
if (i + clen < 2 * M) {
c2[i + clen] += c2[i];
}
}
for (int i = 0; i < Q; ++i) {
int v = G[i] - 1;
if (v < 2 * M) {
answer(c1[v] + c2[v]);
} else {
int f = (v - 2 * M) / clen;
v -= f * clen;
if (f > 0) v += clen;
while (v >= 2 * M) v -= clen;
answer(c2[v]);
}
}
}