/*
#include <bits/stdc++.h>
using namespace std;
const int N = 1e4 + 3;
int n, m;
bool edge[N][N], vis[N];
vector<vector<int>> comps;
vector<int> independent;
int main(){
cin >> n >> m;
for (int i=0; i<m; i++){
int u, v;
cin >> u >> v;
edge[u][v] = 1;
edge[v][u] = 1;
}
for (int sz = n; sz > 0; sz--){
string s;
for (int i=0; i<n-sz; i++)
s += '0';
for (int i=0; i<sz; i++)
s += '1';
do {
bool done = 0;
for (int i=0; i<n; i++){
if (s[i] == '1' and vis[i+1]){
done = 1;
break;
}
}
if (done)
continue;
for (int v = 1; v <= n; v++){
for (int u = v + 1; u <= n; u++){
if (s[v - 1] == '1' and s[u - 1] == '1' and edge[v][u])
done = 1;
}
}
if (done)
continue;
for (int i=0; i<n; i++){
if (s[i] == '1'){
independent.push_back(i+1);
vis[i+1] = 1;
}
}
comps.push_back(independent);
independent.clear();
}
while (next_permutation(s.begin(), s.end()));
}
cout << comps.size() << endl;
for (auto x : comps){
for (auto v : x)
cout << v << " ";
cout << endl;
}
}
*/
/*
./a.out < input_000.txt > output_000.txt
./a.out < input_001.txt > output_001.txt
./a.out < input_002.txt > output_002.txt
./a.out < input_003.txt > output_003.txt
./a.out < input_005.txt > output_005.txt
./a.out < input_006.txt > output_006.txt
./a.out < input_007.txt > output_007.txt
./a.out < input_008.txt > output_008.txt
./a.out < input_009.txt > output_009.txt
*/
/*
#include <bits/stdc++.h>
using namespace std;
const int N = 1e4 + 3;
int n, m, deg[N];
vector<int> g[N], independent;
bool vis[N], bad[N];
vector<vector<int>> comps;
void dfs(int v){
if (v == 0)
return;
independent.push_back(v);
vis[v] = 1;
for (int u:g[v]){
bad[u] = 1;
deg[u]--;
}
int mn_node = 0;
for (int i=1; i<=n; i++){
if (!vis[i] && !bad[i] && deg[mn_node] > deg[i]){
mn_node = i;
}
}
dfs(mn_node);
}
int main(){
cin >> n >> m;
deg[0] = 1e9;
for (int i=0; i<m; i++){
int u, v;
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
deg[v]++;
deg[u]++;
}
while(1){
int mn_node = 0;
for (int i=1; i<=n; i++)
if (!vis[i] && deg[mn_node] > deg[i])
mn_node = i;
if (mn_node == 0)
break;
for (int i=1; i<=n; i++)
bad[i] = 0;
independent.clear();
dfs(mn_node);
comps.push_back(independent);
}
cout << comps.size() << endl;
for (auto x : comps){
for (auto v : x)
cout << v << " ";
cout << endl;
}
}
*/
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int par1[N], par2[N], h[N], mnh[N];
bool vis[N];
vector<int> g[N];
vector<pair<int, int>> bridges;
int root1(int v){
return (par1[v] == -1 ? v : par1[v] = root1(par1[v]));
}
int root2(int v){
return (par2[v] == -1 ? v : par2[v] = root2(par2[v]));
}
void merge1(int u, int v){
// cout << "merge1 : " << u << " " << v << endl;
int r1 = root1(v);
int r2 = root1(u);
par1[r1] = r2;
g[v].push_back(u);
g[u].push_back(v);
}
void merge2(int u, int v){
int r1 = root2(u);
int r2 = root2(v);
if (r1 == r2)
return;
par2[r1] = r2;
g[v].push_back(u);
g[u].push_back(v);
}
void dfs(int v, int p = -1){
// cout << v << endl;
vis[v] = 1;
mnh[v] = h[v];
for (int u : g[v]){
// cout << v << " -- " << u << endl;
if (vis[u]){
if (u != p)
mnh[v] = min(mnh[v], h[u]);
continue;
}
h[u] = h[v] + 1;
dfs(u, v);
mnh[v] = min(mnh[v], mnh[u]);
// cout << u << " : " << mnh[u] << endl;
if (mnh[u] >= h[u])
bridges.push_back({u, v});
}
}
int main(){
int n, m;
scanf("%d %d", &n, &m);
for (int i=1; i<=n; i++)
par1[i] = par2[i] = -1;
for (int i=0; i<m; i++){
int u, v;
scanf("%d %d", &u, &v);
if (root1(u) == root1(v))
merge2(u, v);
else
merge1(u, v);
}
for (int v = 1; v <= n; v++){
if (!vis[v]){
// cout << "---------------\n";
dfs(v);
}
}
for (auto [u, v] : bridges)
printf("%d %d\n", u, v);
}
/*
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int par1[N], par2[N], h[N], mnh[N];
bool vis[N];
vector<int> g[N];
vector<pair<int, int>> bridges;
int root1(int v){
return (par1[v] == -1 ? v : par1[v] = root1(par1[v]));
}
int root2(int v){
return (par2[v] == -1 ? v : par2[v] = root2(par2[v]));
}
void merge1(int u, int v){
int r1 = root1(v);
int r2 = root1(u);
par1[r1] = r2;
g[v].push_back(u);
g[u].push_back(v);
}
void merge2(int u, int v){
int r1 = root2(u);
int r2 = root2(v);
if (r1 == r2)
return;
par2[r1] = r2;
g[v].push_back(u);
g[u].push_back(v);
}
void dfs(int v, int p = -1){
vis[v] = 1;
mnh[v] = h[v];
for (int u : g[v]){
if (vis[u]){
if (u != p)
mnh[v] = min(mnh[v], h[u]);
continue;
}
h[u] = h[v] + 1;
dfs(u, v);
mnh[v] = min(mnh[v], mnh[u]);
if (mnh[u] >= h[u])
bridges.push_back({u, v});
}
}
int main(){
int n, m;
scanf("%d%d", &n, &m);
for (int i=1; i<=n; i++)
par1[i] = par2[i] = -1;
for (int i=0; i<m; i++){
int u, v;
scanf("%d%d", &u, &v);
if (root1(u) == root1(v))
merge2(u, v);
else
merge1(u, v);
}
for (int v = 1; v <= n; v++)
if (!vis[v])
dfs(v);
for (auto [u, v] : bridges)
printf("%d %d\n", u, v);
}
*/
Compilation message
pipes.cpp: In function 'int main()':
pipes.cpp:224:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
224 | scanf("%d %d", &n, &m);
| ~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:231:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
231 | scanf("%d %d", &u, &v);
| ~~~~~^~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Wrong number of edges |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
3164 KB |
Output is correct |
2 |
Incorrect |
3 ms |
2908 KB |
Wrong number of edges |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
85 ms |
3152 KB |
Output is correct |
2 |
Incorrect |
90 ms |
2948 KB |
Wrong number of edges |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
142 ms |
3668 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
233 ms |
5452 KB |
Output is correct |
2 |
Runtime error |
219 ms |
19028 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
305 ms |
10584 KB |
Output is correct |
2 |
Runtime error |
283 ms |
25644 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
469 ms |
11996 KB |
Output is correct |
2 |
Runtime error |
490 ms |
42472 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
652 ms |
14136 KB |
Output is correct |
2 |
Runtime error |
606 ms |
50520 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
783 ms |
18032 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
944 ms |
30340 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |