| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 951581 | Boycl07 | Keys (IOI21_keys) | 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 "keys.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(int i = 1; i <= n; ++i)
#define forn(i, l, r) for(int i = l; i <= r; ++i)
#define ford(i, r, l) for(int i = r; i >= l; --i)
#define FOR(i, n) for(int i = 0; i < n; ++i)
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define endl "\n"
#define task ""
#define sz(a) int(a.size())
#define all(a) (a).begin(), (a).end()
#define bit(i, mask) (mask >> i & 1)
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
inline int readInt() {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();int n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline ll readLong() {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();ll n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline string readString() {char c;while(c=getchar(),c==' '||c=='\n'||c=='\t');string s({c});while(c=getchar(),c!=EOF&&c!=' '&&c!='\n'&&c!='\t')s+=c;return s;}
struct DSU
{
vector<int> par;
vector<int> sz;
void init(int n)
{
par.assign(n + 1, 0);
sz.assign(n + 1, 0);
FOR(i, n) par[i] = i, sz[i] = 1;
}
int find_set(int u) {return u == par[u] ? u : par[u] = find_set(par[u]);}
};
vector<int> find_reachable(vector<int> r, vector<int> u_, vector<int> v_, vector<int> c_)
{
int n = sz(r), m = sz(c_);
DSU dsu;
dsu.init(n);
vector<bool> ok(n, false);
vector<vector<pii>> g(n);
for(int i = 0; i < m; ++i)
{
int u = u_[i], v = v_[i], c = c_[i];
g[u].pb({v, c});
g[v].pb({u, c});
}
vector<int> res;
while(true)
{
bool flag = 0;
vector<vector<int>> pot(n);
vector<bool> vis(n, false);
vector<bool> keys(n, false);
vector<int> cur_keys;
function<void(int)> bfs = [&](int s)
{
for(int x : cur_keys) keys[x] = 0, pot[x].clear();
cur_keys.clear();
queue<int> q;
q.push(s);
vis[s] = 1;
vector<int> cur;
while(sz(q))
{
int u = q.front(); q.pop();
cur.pb(u);
if(!keys[r[u]])
{
keys[r[u]] = 1;
cur_keys.pb(r[u]);
for(int v : pot[r[u]])
{
int c = dsu.find_set(v);
if(c != s)
{
dsu.par[s] = c;
vis[c] = 1;
return;
}
if(vis[v]) continue;
vis[v] = 1;
q.push(v);
}
}
for(pii e : g[u])
{
int v = e.fi, c = e.se;
if(!keys[c])
pot[c].pb(v);
else
{
int c = dsu.find_set(v);
if(c != s)
{
dsu.par[s] = c;
vis[c] = 1;
return;
}
if(vis[v]) continue;
vis[v] = 1;
q.push(v);
}
}
ok[s] = 1;
if(res.empty() || sz(res) < sz(cur)) res = cur;
else if(sz(res) == sz(cur)) for(int x : cur) res.pb(x);
}
};
FOR(i, n) if(dsu.find_set(i) == i && !ok[i] && !vis[i])
bfs(i), flag = 1;
if(!flag) break;
}
vector<int> out(n, 0);
for(int x : res) out[x] = 1;
return out;
}
int main() {
int n, m;
freopen("keys.inp", "r", stdin);
freopen("keys.out", "w", stdout);
assert(2 == scanf("%d%d", &n, &m));
std::vector<int> r(n), u(m), v(m), c(m);
for(int i=0; i<n; i++) {
assert(1 == scanf("%d", &r[i]));
}
for(int i=0; i<m; i++) {
assert(3 == scanf("%d %d %d", &u[i], &v[i], &c[i]));
}
fclose(stdin);
std::vector<int> ans = find_reachable(r, u, v, c);
for (int i = 0; i < (int) ans.size(); ++i) {
if(i) putchar(' ');
putchar(ans[i]+'0');
}
printf("\n");
return 0;
}