oj.uz

Submission #441210

# Submission time Handle Problem Language Result Execution time Memory
441210 2021-07-04T16:20:25 Z sinamhdv Pipes (CEOI15_pipes) C++11
100 / 100
 4524 ms 15616 KB 
// CEOI15_pipes
// 1st solution (reading input twice)
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1000 * 1000 * 1000 + 7;
const int INF = 1e9 + 100;
const ll LINF = 1e18 + 100;

#ifdef DEBUG
#define dbg(x) cout << #x << " = " << (x) << endl << flush;
#define dbgr(s, f) { cout << #s << ": "; for (auto _ = (s); _ != (f); _++) cout << *_ << ' '; cout << endl << flush; }
#else
#define dbg(x) ;
#define dbgr(s, f) ;
#endif
#define FOR(i, a, b) for (int i = (a); i < (int)(b); i++)
#define fast_io ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define mp make_pair
#define fr first
#define sc second
#define endl '\n'

#define MAXN 100010
#define LOGN 19

int n, m;
bitset<60 * MAXN> intree;
vector<int> adj[MAXN];
int lpar[LOGN][MAXN], sttime[MAXN], fntime[MAXN], timer;
bitset<MAXN> mark;
int val[MAXN];

int dpar[MAXN];
int getroot(int x)
{
	return dpar[x] == x ? x : dpar[x] = getroot(dpar[x]);
}
bool merge(int x, int y)
{
	x = getroot(x);
	y = getroot(y);
	if (x == y) return false;
	dpar[x] = y;
	return true;
}

void dfs1(int v)
{
	sttime[v] = timer++;
	mark[v] = true;
	for (int u : adj[v]) if (!mark[u])
	{
		lpar[0][u] = v;
		dfs1(u);
	}
	fntime[v] = timer;
}

void dfs2(int v)
{
	mark[v] = true;
	for (int u : adj[v]) if (!mark[u]) dfs2(u), val[v] += val[u];
	if (lpar[0][v] && val[v] == 0) cout << v << ' ' << lpar[0][v] << endl;
}

inline bool isanc(int x, int y)
{
	return sttime[x] <= sttime[y] && fntime[y] <= fntime[x];
}

int getlca(int x, int y)
{
	if (isanc(x, y)) return x;
	if (isanc(y, x)) return y;
	for (int i = LOGN - 1; i >= 0; i--)
		if (lpar[i][x] && !isanc(lpar[i][x], y))
			x = lpar[i][x];
	return lpar[0][x];
}

int32_t main(void)
{
	fast_io;
	cin >> n >> m;

	iota(dpar, dpar + n + 5, 0);

	FOR(i, 0, m)
	{
		int x, y;
		cin >> x >> y;
		if (merge(x, y))
		{
			intree[i] = 1;
			adj[x].pb(y);
			adj[y].pb(x);
		}
	}

	FOR(i, 1, n + 1) if (!mark[i]) dfs1(i);

	FOR(i, 1, LOGN) FOR(j, 1, n + 1) lpar[i][j] = lpar[i - 1][lpar[i - 1][j]];

	cin.seekg(0);
	cin >> n >> m;
	FOR(i, 0, m)
	{
		int x, y;
		cin >> x >> y;
		if (intree[i]) continue;
		val[x]++;
		val[y]++;
		val[getlca(x, y)] -= 2;
	}

	mark.reset();
	FOR(i, 1, n + 1) if (!mark[i]) dfs2(i);

	return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2764 KB Output is correct
2 Correct 2 ms 2764 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 3276 KB Output is correct
2 Correct 8 ms 3276 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 293 ms 3188 KB Output is correct
2 Correct 286 ms 3424 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 554 ms 3912 KB Output is correct
2 Correct 630 ms 3912 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 907 ms 5664 KB Output is correct
2 Correct 796 ms 6496 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1271 ms 11296 KB Output is correct
2 Correct 1190 ms 11324 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2048 ms 12560 KB Output is correct
2 Correct 2093 ms 12768 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3177 ms 14824 KB Output is correct
2 Correct 2961 ms 15032 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3908 ms 14820 KB Output is correct
2 Correct 3643 ms 14980 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4524 ms 14224 KB Output is correct
2 Correct 4441 ms 15616 KB Output is correct