oj.uz

Submission #81945

# Submission time Handle Problem Language Result Execution time Memory
81945 2018-10-28T08:13:45 Z Saboon Pipes (CEOI15_pipes) C++17
50 / 100
 1292 ms 7344 KB 
#include <iostream>
#include <queue>
#include <stack>
#include <vector>
#include <cstring>
#include <cmath>
#include <map>
#include <unordered_map>
#include <set>
#include <algorithm>
#include <iomanip>
#define F first
#define S second
#define PB push_back
#define PF push_front
#define MP make_pair
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int maxn = 3e4 + 10;
const ll inf = 1e18 + 1000;

int h[maxn], par[maxn][22], dp[maxn];
bool cut[maxn];

int lca (int v, int u) {
	if (h[v] < h[u])
		swap (v, u);
	for (int i = 20; i >= 0; i--)
		if (h[v] - (1 << i) >= h[u])
			v = par[v][i];
	if (v == u)
		return v;
	for (int i = 20; i >= 0; i--) {
		if (par[v][i] != par[u][i]) {
			v = par[v][i];
			u = par[u][i];
		}
	}
	return par[v][0];
}

vector <int> g[maxn];

void dfs2 (int v, int p) {
	dp[v] = h[v];
	for (auto w : g[v]) {
		if (w != p) {
			h[w] = h[v] + 1;
			dfs2 (w, v);
		}
	}
}

void dfs1 (int v, int p) {
	par[v][0] = p;
	for (int i = 1; i <= 20; i++) {
		if (par[v][i - 1] != -1)
			par[v][i] = par[par[v][i - 1]][i - 1];
		else
			par[v][i] = -1;
	}
	for (auto u : g[v]) {
		if (u != p) {
			dfs1 (u, v);
		if (h[v] > h[u])
			cut[u] = cut[v];
		}
	}
}

void dfs (int v, int p = -1) {
	for (auto w : g[v]) {
		if (w != p) {
			dfs (w, v);
			dp[v] = min (dp[v], dp[w]);
		}
	}
	cut[v] &= (h[v] <= dp[v]);
}

int dpar[maxn];
int get_par (int v) {
	if (dpar[v] < 0)
		return v;
	return dpar[v] = get_par (dpar[v]);
}

int n;
void merge (int v, int u) {
	int vpar = get_par (v);
	dfs (vpar);
	dfs1 (v, u);
	cut[v] = 1;
	h[v] = h[u] + 1;
	dfs2 (v, u);
	dpar[get_par(u)] += dpar[get_par(v)];
	dpar[get_par(v)] = get_par(u);
	g[u].PB (v);
	g[v].PB (u);
}		

bool mark[maxn];

int main() {
	memset (par, -1, sizeof par);
	memset (dpar, -1, sizeof dpar);
	int m;
	cin >> n >> m;
	while (m --) {
		int v, u;
		cin >> v >> u;
		int vpar = get_par(v), upar = get_par(u);
		if (vpar != upar) {
			if (dpar[vpar] < dpar[upar])
				swap (v, u);
			merge (v, u);
		}
		else {
			int w = lca (v, u);
			dp[v] = min (dp[v], h[w]);
			dp[u] = min (dp[u], h[w]);
		}
	}
	
	for (int i = 1; i <= n; i++) {
		int v = get_par (i);
		if (!mark[v]) {
			mark[v] = 1;
			dfs (v);
		}
	}
	for (int i = 1; i <= n; i++)
		if (cut[i])
			cout << i << " " << par[i][0] << endl;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 3712 KB Output is correct
2 Correct 4 ms 3712 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 3968 KB Output is correct
2 Correct 13 ms 3940 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 382 ms 3932 KB Output is correct
2 Correct 377 ms 3920 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 754 ms 4164 KB Output is correct
2 Correct 812 ms 4224 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1292 ms 4728 KB Output is correct
2 Correct 1047 ms 5048 KB Output is correct

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 9 ms 7296 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 8 ms 7296 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 8 ms 7296 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 8 ms 7248 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 8 ms 7344 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -