Submission #604912

# Submission time Handle Problem Language Result Execution time Memory
604912 2022-07-25T10:47:40 Z valerikk Pipes (CEOI15_pipes) C++17
0 / 100
1201 ms 65536 KB
#include <bits/stdc++.h>
 
using namespace std;
 
#define x first
#define y second
#define all(a) begin(a), end(a)
#define sz(a) ((int) (a).size())
 
using ll = long long;
using ld = long double;
 
const int N = 1e5 + 7;

struct Dsu {
	int dsu[N];
 
	int get(int u) {
		return dsu[u] == u ? u : dsu[u] = get(dsu[u]);
	}
 
	void merge(int u, int v) {
		u = get(u);
		v = get(v);
		if (u != v) {
			dsu[u] = v;
		}
	}
 
	bool same(int u, int v) {
		return get(u) == get(v);
	}
 
	Dsu() {
		iota(all(dsu), 0);
	}
} dsu1, dsu2;
 
int n, m;
list<int> g[N];
int *tin = &dsu1.dsu[0];
int *fup = &dsu2.dsu[0];
int t = 0;
bool vis[N];
 
void dfs(int u, int p = -1) {
	vis[u] = true;
	tin[u] = t++;
	fup[u] = tin[u];
	for (const int &v : g[u]) {
		if (v == p) continue;
		if (!vis[v]) {
			dfs(v, u);
			fup[u] = min(fup[u], fup[v]);
			if (fup[v] > tin[u] && !dsu2.same(u, v)) {
				printf("%d %d\n", u, v);
			}
		} else {
			fup[u] = min(fup[u], tin[v]);
		}
	}
}
 
int main() {
	scanf("%d%d", &n, &m);
	for (int i = 0; i < m; ++i) {
		int a, b;
		scanf("%d%d", &a, &b);
		if (dsu1.same(a, b) && dsu2.same(a, b)) continue;
		g[a].push_back(b);
		g[b].push_back(a);
		if (dsu1.same(a, b)) {
			dsu2.merge(a, b);
		} else {
			dsu1.merge(a, b);
		}
	}
	for (int i = 1; i <= n; ++i) {
		if (!vis[i]) {
			dfs(i);
		}
	}
	return 0;
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:65:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |  scanf("%d%d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:68:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |   scanf("%d%d", &a, &b);
      |   ~~~~~^~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Runtime error 42 ms 65536 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 43 ms 65536 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 97 ms 4172 KB Output is correct
2 Runtime error 132 ms 65536 KB Execution killed with signal 9
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 214 ms 65536 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 305 ms 8572 KB Output is correct
2 Runtime error 257 ms 65536 KB Execution killed with signal 9
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 407 ms 18912 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 637 ms 21236 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 829 ms 25352 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 1041 ms 25356 KB Memory limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 1201 ms 24216 KB Memory limit exceeded
2 Halted 0 ms 0 KB -