#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n, m;
vector<int> link[500002], revLink[500002];
int ex[500002], ey[500002];
int ans[500002]; /// 0: ���� �� ��, 1: ��ĥ X, 2: ��ĥ O
vector<int> ansVec;
int deg[500002];
int bccCnt;
int depth[500002], bccNum[500002], bccDeg[500002], pushed[500002];
vector<int> vertices;
int checkBCC(int x){
int ret = depth[x];
vertices.push_back(x);
for(auto y: link[x]){
if(ans[y]) continue;
if(depth[y]) ret = min(ret, depth[y]);
else depth[y] = depth[x] + 1, ret = min(ret, checkBCC(y));
}
if(ret >= depth[x]){
int B = ++bccCnt;
while(1){
int tmp = vertices.back(); vertices.pop_back();
bccNum[tmp] = B;
if(tmp == x) break;
}
}
return ret;
}
void colorBCC(int x, int c, int b){
vector<int> sumLink = link[x];
for(auto y: revLink[x]) sumLink.push_back(y);
ans[x] = c;
// printf("In ColorBCC: colored %d as %d\n", x, c);
for(auto y: sumLink){
if(bccNum[y] != b || ans[y]) continue;
colorBCC(y, 3-c, b);
}
}
int main(){
scanf("%d %d", &n, &m);
for(int i=1; i<=m; i++){
int x, y;
scanf("%d %d", &x, &y);
ex[i] = x, ey[i] = y;
}
while(1){
/// �ڵ� ������ �� ã��
for(int i=1; i<=n; i++) deg[i] = pushed[i] = 0;
for(int i=1; i<=n; i++) link[i].clear(), revLink[i].clear();
for(int i=1; i<=m; i++) if(!ans[ex[i]] && !ans[ey[i]]){
link[ex[i]].push_back(ey[i]);
revLink[ey[i]].push_back(ex[i]);
deg[ex[i]]++;
}
queue<int> que;
for(int i=1; i<=n; i++) if(!ans[i] && !deg[i]) pushed[i] = 1, que.push(i);
while(!que.empty()){
int x = que.front(); que.pop();
int c = 2;
for(int y: link[x]) if(ans[y] == 2) c = 1;
for(int y: revLink[x]) if(ans[y] == 2) c = 1;
ans[x] = c;
// printf("In queue: colored %d as %d\n", x, c);
if(ans[x] == 2){
for(auto y: link[x]) if(!pushed[y]) pushed[y] = 1, que.push(y);
for(auto y: revLink[x]) if(!pushed[y]) pushed[y] = 1, que.push(y);
}
for(auto y: revLink[x]){
deg[y]--;
if(!ans[y] && !deg[y] && !pushed[y]) pushed[y] = 1, que.push(y);
}
}
/// ��ĥ�� �� �ƴ��� Ȯ��
bool Done = 1;
for(int i=1; i<=n; i++) if(!ans[i]) Done = 0;
if(Done) break;
bccCnt = 0;
for(int i=1; i<=n; i++) bccNum[i] = depth[i] = bccDeg[i] = 0;
vertices.clear();
for(int i=1; i<=n; i++) if(!ans[i] && !depth[i] && !bccNum[i]) depth[i] = 1, checkBCC(i);
for(int i=1; i<=m; i++) if(!ans[ex[i]] && !ans[ey[i]] && bccNum[ex[i]] != bccNum[ey[i]]) bccDeg[bccNum[ex[i]]]++;
int bccTarget = -1;
for(int i=1; i<=bccCnt; i++) if(!bccDeg[i]) bccTarget = i;
assert(bccTarget != -1);
int start = -1;
for(int i=1; i<=n; i++) if(!ans[i] && bccNum[i] == bccTarget) start = i;
assert(start != -1);
/// ��ĥ�� �ش�
colorBCC(start, 1, bccTarget);
/// �������� �̾��� ����� ��ĥ�� �ش�
for(int i=1; i<=n; i++) if(bccNum[i] == bccTarget){
if(ans[i] == 0) exit(0);
if(ans[i] == 2){
for(int j: revLink[i]) if(!ans[j]) ans[j] = 1;
for(int j: link[i]) if(!ans[j]) ans[j] = 1;
}
}
}
for(int i=1; i<=n; i++) if(ans[i] == 2) ansVec.push_back(i);
printf("%d\n", (int)ansVec.size());
for(auto x: ansVec) printf("%d ", x);
}
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:51:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
51 | scanf("%d %d", &n, &m);
| ~~~~~^~~~~~~~~~~~~~~~~
Main.cpp:54:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
54 | scanf("%d %d", &x, &y);
| ~~~~~^~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
200 ms |
65740 KB |
Output is correct |
2 |
Correct |
234 ms |
65336 KB |
Output is correct |
3 |
Correct |
13 ms |
23764 KB |
Output is correct |
4 |
Correct |
62 ms |
34604 KB |
Output is correct |
5 |
Correct |
117 ms |
50888 KB |
Output is correct |
6 |
Correct |
162 ms |
56016 KB |
Output is correct |
7 |
Correct |
128 ms |
52860 KB |
Output is correct |
8 |
Correct |
203 ms |
54948 KB |
Output is correct |
9 |
Correct |
366 ms |
59788 KB |
Output is correct |
10 |
Correct |
317 ms |
57676 KB |
Output is correct |
11 |
Correct |
402 ms |
57540 KB |
Output is correct |
12 |
Correct |
459 ms |
52816 KB |
Output is correct |
13 |
Correct |
303 ms |
53476 KB |
Output is correct |
14 |
Correct |
234 ms |
53620 KB |
Output is correct |
15 |
Correct |
226 ms |
53804 KB |
Output is correct |
16 |
Correct |
216 ms |
53912 KB |
Output is correct |
17 |
Correct |
70 ms |
28664 KB |
Output is correct |
18 |
Correct |
104 ms |
32992 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
185 ms |
65672 KB |
Output is correct |
2 |
Correct |
163 ms |
54748 KB |
Output is correct |
3 |
Correct |
126 ms |
51504 KB |
Output is correct |
4 |
Correct |
409 ms |
56668 KB |
Output is correct |
5 |
Correct |
477 ms |
56808 KB |
Output is correct |
6 |
Correct |
331 ms |
61024 KB |
Output is correct |
7 |
Correct |
497 ms |
61096 KB |
Output is correct |
8 |
Runtime error |
2725 ms |
117184 KB |
Execution killed with signal 6 |
9 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
15 ms |
24144 KB |
Output is correct |
2 |
Correct |
14 ms |
24060 KB |
Output is correct |
3 |
Correct |
15 ms |
24032 KB |
Output is correct |
4 |
Correct |
14 ms |
24096 KB |
Output is correct |
5 |
Correct |
15 ms |
24148 KB |
Output is correct |
6 |
Correct |
15 ms |
24228 KB |
Output is correct |
7 |
Correct |
17 ms |
24180 KB |
Output is correct |
8 |
Correct |
56 ms |
24156 KB |
Output is correct |
9 |
Runtime error |
36 ms |
48228 KB |
Execution killed with signal 6 |
10 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
200 ms |
65740 KB |
Output is correct |
2 |
Correct |
234 ms |
65336 KB |
Output is correct |
3 |
Correct |
13 ms |
23764 KB |
Output is correct |
4 |
Correct |
62 ms |
34604 KB |
Output is correct |
5 |
Correct |
117 ms |
50888 KB |
Output is correct |
6 |
Correct |
162 ms |
56016 KB |
Output is correct |
7 |
Correct |
128 ms |
52860 KB |
Output is correct |
8 |
Correct |
203 ms |
54948 KB |
Output is correct |
9 |
Correct |
366 ms |
59788 KB |
Output is correct |
10 |
Correct |
317 ms |
57676 KB |
Output is correct |
11 |
Correct |
402 ms |
57540 KB |
Output is correct |
12 |
Correct |
459 ms |
52816 KB |
Output is correct |
13 |
Correct |
303 ms |
53476 KB |
Output is correct |
14 |
Correct |
234 ms |
53620 KB |
Output is correct |
15 |
Correct |
226 ms |
53804 KB |
Output is correct |
16 |
Correct |
216 ms |
53912 KB |
Output is correct |
17 |
Correct |
70 ms |
28664 KB |
Output is correct |
18 |
Correct |
104 ms |
32992 KB |
Output is correct |
19 |
Correct |
185 ms |
65672 KB |
Output is correct |
20 |
Correct |
163 ms |
54748 KB |
Output is correct |
21 |
Correct |
126 ms |
51504 KB |
Output is correct |
22 |
Correct |
409 ms |
56668 KB |
Output is correct |
23 |
Correct |
477 ms |
56808 KB |
Output is correct |
24 |
Correct |
331 ms |
61024 KB |
Output is correct |
25 |
Correct |
497 ms |
61096 KB |
Output is correct |
26 |
Runtime error |
2725 ms |
117184 KB |
Execution killed with signal 6 |
27 |
Halted |
0 ms |
0 KB |
- |