oj.uz

Submission #604923

# Submission time Handle Problem Language Result Execution time Memory
604923 2022-07-25T10:51:33 Z valerikk Pipes (CEOI15_pipes) C++17
0 / 100
 1224 ms 8692 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;

int mem[2 * N];

int *dsu1 = &mem[0];
int *dsu2 = &mem[N];

int get1(int u) {
	return dsu1[u] == u ? u : dsu1[u] = get1(dsu1[u]);
}

int get2(int u) {
	return dsu2[u] == u ? u : dsu2[u] = get2(dsu2[u]);
}

void merge1(int u, int v) {
	u = get1(u);
	v = get1(v);
	if (u != v) {
		dsu1[u] = v;
	}
}

void merge2(int u, int v) {
	u = get2(u);
	v = get2(v);
	if (u != v) {
		dsu2[u] = v;
	}
}

bool same1(int u, int v) {
	return get1(u) == get1(v);
}

bool same2(int u, int v) {
	return get2(u) == get2(v);
}

int n, m;
vector<int> g[N];
int *tin = &mem[0];
int *fup = &mem[N];
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] && !same2(u, v)) {
				printf("%d %d\n", u + 1, v + 1);
			}
		} 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);
		--a, --b;
		if (same1(a, b) && same2(a, b)) continue;
		g[a].push_back(b);
		g[b].push_back(a);
		if (same1(a, b)) {
			merge2(a, b);
		} else {
			merge1(a, b);
		}
	}
	for (int i = 0; i < n; ++i) {
		if (!vis[i]) {
			dfs(i);
		}
	}
	return 0;
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:78:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |  scanf("%d%d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:81:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |   scanf("%d%d", &a, &b);
      |   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 2644 KB Wrong number of edges
2 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 2644 KB Wrong number of edges
2 Halted 0 ms 0 KB -

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 104 ms 2668 KB Output is correct
2 Incorrect 107 ms 2672 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 188 ms 2716 KB Output is correct
2 Incorrect 220 ms 2712 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 287 ms 2820 KB Output is correct
2 Incorrect 268 ms 2872 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 346 ms 3184 KB Output is correct
2 Incorrect 291 ms 3184 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 570 ms 3264 KB Output is correct
2 Incorrect 562 ms 3256 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 777 ms 3412 KB Output is correct
2 Incorrect 708 ms 3416 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 976 ms 3416 KB Output is correct
2 Incorrect 911 ms 3416 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1224 ms 3368 KB Output is correct
2 Incorrect 1116 ms 8692 KB Wrong number of edges
3 Halted 0 ms 0 KB -