#include "bits/stdc++.h"
#include "grader.h"
using namespace std;
#define ll long long
#define forn(i,n) for(int i=0;i<n;i++)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(),v.rend()
#define pb push_back
#define sz(a) (int)a.size()
vector<int> bfs(int start, vector<vector<int>>& adj) {
int n = sz(adj);
vector<int> dist(n, -1);
dist[start] = 0;
queue<int> q;
q.push(start);
while(!q.empty()) {
int u = q.front();
q.pop();
for(int v: adj[u]) {
if(dist[v] == -1) {
dist[v] = dist[u] + 1;
q.push(v);
}
}
}
return dist;
}
void dfs(int u, vector<bool>& vis, vector<vector<int>>& adj, vector<int>& par) {
vis[u] = true;
for(int v: adj[u]) {
if(!vis[v]) {
par[v] = u;
dfs(v, vis, adj, par);
}
}
}
map<vector<int>, int> mp;
int amogus = 0;
void rec(vector<int> v) {
if(sz(v) == 3) {
if(mp.count(v)) return;
mp[v] = amogus++;
} else {
for(int i = 0; i <= 2; ++i) {
v.pb(i);
rec(v);
v.pop_back();
}
}
}
void encode(int n, int h, int m, int *v1, int *v2){
vector<vector<int>> adj(n);
for(int i = 0; i < m; ++i) {
adj[v1[i]].pb(v2[i]);
adj[v2[i]].pb(v1[i]);
}
vector<vector<int>> dist(n);
forn(i, n) dist[i] = bfs(i, adj);
for(int i = 0;i < h; ++i) {
for(int j = 0; j < 10; ++j) {
if(dist[0][i] & (1 << j)) encode_bit(1);
else encode_bit(0);
}
}
vector<bool> vis(n, false);
vector<int> parent(n);
iota(all(parent), 0);
dfs(0, vis, adj, parent);
for(int i = 0; i < n; ++i) {
for(int j = 0; j < 10; ++j) {
if(parent[i] & (1 << j)) encode_bit(1);
else encode_bit(0);
}
}
//dist[node][i] = dist[parent[node]][i] (0)
//dist[node][i] = dist[parent[node]][i] - 1 (1)
//dist[node][i] = dist[parent[node]][i] + 1 (2)
rec({});
for(int j = 0; j < h; ++j) {
vector<int> v;
for(int i = 0; i < n; ++i) {
if(dist[i][j] == dist[parent[i]][j]) v.pb(0);
else if(dist[i][j] == dist[parent[i]][j] - 1) v.pb(1);
else {
assert(dist[i][j] == dist[parent[i]][j] + 1);
v.pb(2);
}
}
for(int i = 0; i + 2 < n; i += 3) {
for(int f = 0; f < 5; ++f) {
if(mp[{v[i], v[i + 1], v[i + 2]}] & (1 << f)) {
encode_bit(1);
} else encode_bit(0);
}
}
if(n % 3 == 1) {
for(int f = 0; f < 2; ++f) {
if(v.back() & (1 << f)) encode_bit(1);
else encode_bit(0);
}
} else if(n % 3 == 2) {
for(int k = sz(v) - 2; k < sz(v); ++k) {
for(int f = 0; f < 2; ++f) {
if(v[k] & (1 << f)) encode_bit(1);
else encode_bit(0);
}
}
}
}
}
/*
void solve() {
}
int32_t main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int t = 1;
//cin >> t;
while(t--) {
solve();
}
}
*/
Compilation message
/usr/bin/ld: /tmp/ccfZeJTu.o: in function `main':
grader_decoder.c:(.text.startup+0x126): undefined reference to `decode(int, int)'
collect2: error: ld returned 1 exit status
