Submission #1021660

# Submission time Handle Problem Language Result Execution time Memory
1021660 2024-07-13T02:02:14 Z idiotcomputer Pipes (CEOI15_pipes) C++11
40 / 100
820 ms 65536 KB
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz size 

const int mxN = 1e5;
vector<int> adj[mxN];
int d[mxN];
int low[mxN];

void dfs(int c, int depth, int p){
	d[c] = depth;
	low[c] = d[c];
	int op = p;
	for (int i : adj[c]){
		if (i == p){p = -1; continue;}
		if (d[i] != -1){ low[c] = min(low[c],d[i]); continue;}
		dfs(i,depth+1,c);
		low[c] = min(low[c], low[i]);
	}
	if (low[c] >= depth && op != -1) cout << c+1 << " " << op+1 << '\n';
}

int p[mxN][2];
int ssize[mxN][2];

int gpar(int c, int w){
	if (p[c][w] == c) return c;
	p[c][w] = gpar(p[c][w],w);
	return p[c][w];
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int n,m;
	cin >> n >> m;
	for (int i = 0; i < n; i++) for (int j = 0; j < 2; j++) {p[i][j] = i; ssize[i][j] = 1;}

	int a,b;
	int x,y;
	int cnt = 0;
	for (int i = 0; i < m; i++){
		cin >> a >> b;
		a -= 1;
		b -= 1;
		x = gpar(a,0);
		y = gpar(b,0);
		if (x != y){
			adj[a].pb(b);
			adj[b].pb(a);
			cnt++;
			if (ssize[x][0] < ssize[y][0]) swap(x,y);
			ssize[x][0] += ssize[y][0];
			p[y][0] = x;
			continue;
		}
		x = gpar(a,1);
		y = gpar(b,1);
		if (x == y) continue;
		if (ssize[x][1] < ssize[y][1]) swap(x,y);
		ssize[x][1] += ssize[y][1];
		p[y][1] = x;
		adj[a].pb(b);
		adj[b].pb(a);
		cnt++;
	}
	if (cnt > 2*n-2) while(true) continue;
	for (int i = 0; i < n; i++) d[i] = -1;
	for (int i = 0; i < n; i++) if (d[i] == -1) dfs(i,0,-1);
	return 0;	
}

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2652 KB Output is correct
2 Correct 2 ms 2676 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 3 ms 3416 KB Output is correct
2 Correct 3 ms 3164 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 65 ms 8496 KB Output is correct
2 Correct 92 ms 7932 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 108 ms 12816 KB Output is correct
2 Correct 126 ms 13904 KB Output is correct
# Verdict Execution time Memory Grader output
1 Runtime error 189 ms 20052 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 263 ms 29552 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 386 ms 41900 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 507 ms 53556 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 645 ms 64136 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 820 ms 65536 KB Memory limit exceeded
2 Halted 0 ms 0 KB -