oj.uz

Submission #125128

# Submission time Handle Problem Language Result Execution time Memory
125128 2019-07-04T16:31:10 Z eriksuenderhauf Potemkin cycle (CEOI15_indcyc) C++11
40 / 100
 1000 ms 3192 KB 
//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
#define mem(a,v) memset((a), (v), sizeof (a))
#define enl printf("\n")
#define case(t) printf("Case #%d: ", (t))
#define ni(n) scanf("%d", &(n))
#define nl(n) scanf("%I64d", &(n))
#define nai(a, n) for (int i = 0; i < (n); i++) ni(a[i])
#define nal(a, n) for (int i = 0; i < (n); i++) nl(a[i])
#define pri(n) printf("%d\n", (n))
#define prl(n) printf("%I64d\n", (n))
#define pii pair<int, int>
#define pil pair<int, long long>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vil vector<pil>
#define vll vector<pll>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef cc_hash_table<int,int,hash<int>> ht;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
const double pi = acos(-1);
const int MOD = 1e9 + 7;
const int INF = 1e9 + 7;
const int MAXN = 1e3 + 5;
const int MAXM = 1e5 + 5;
const double eps = 1e-9;
int U[MAXM], V[MAXM], ap[MAXM], mrk[MAXM];
int lo[MAXN], disc[MAXN], ti = 1, inSt[MAXN];
vi adj[MAXN];

void dfs(int u, int p=0) {
	lo[u] = disc[u] = ti++;
	for (int i: adj[u]) {
		int v = U[i]^V[i]^u;
		if (!disc[v]) {
			dfs(v, u);
			lo[u] = min(lo[u], lo[v]);
			if (lo[v] > disc[u])
				ap[i] = 1;
		} else if (v != p)
			lo[u] = min(lo[u], disc[v]);
	}
}

stack<int> st;

void solve(int u, int root, int d=0, int p=0) {
	disc[u] = 1;
	bool fl = 0;
	//cerr << "current node: " << u << " " << d << " " << p << "\n";
	for (int i: adj[u]) {
		int v = U[i]^V[i]^u;
		if (ap[i] || v == p)
			continue;
		if (mrk[i] && inSt[v])
			return;
		if (mrk[i])
			continue;
		if (disc[v] && (v != root || (v == root && d <= 2))) {
			disc[u] = 0;
			return;
		}
		if (v == root && d > 2)
			fl = 1;
	}
	st.push(u);
	inSt[u] = 1;
	if (fl) {
		while (!st.empty()) {
			printf("%d ", st.top());
			st.pop();
		}
		printf("\n");
		exit(0);
	}
	random_shuffle(adj[u].begin(), adj[u].end());
	for (int i: adj[u]) {
		int v = U[i]^V[i]^u;
		if (ap[i] || v == p || mrk[i]) continue;
		solve(v, root, d+1, u);
		mrk[i] = 1;
	}
	disc[u] = 0;
	inSt[u] = 0;
	st.pop();
}

//int deg[MAXN];

int main() {
	srand(time(0));
	int n, m;
	scanf("%d %d", &n, &m);
	for (int i = 1; i <= m; i++) {
		scanf("%d %d", U+i, V+i);
		adj[U[i]].pb(i);
		adj[V[i]].pb(i);
		//deg[U[i]]++, deg[V[i]]++;
	}
	//for (int i= 1; i <= n; i++)
	//	if (deg[i] > 70)
	//		cerr << i << " " << deg[i] << "\n";
	for (int i = 1; i <= n; i++)
		if (!disc[i])
			dfs(i);
	//for (int i = 1; i <= m; i++)
	//	cerr << "edge " << U[i] << " " << V[i] << " stat: " << ap[i] << "\n";
	for (int i = 1; i <= n; i++) {
		mem(disc, 0);
		mem(inSt, 0);
		mem(mrk, 0);
		//cerr << "check root: " << i << "\n";
		solve(i, i);
		while (!st.empty())
			st.pop();
		//cerr << "\n";
	}
	printf("no\n");
    return 0;
}

Compilation message

indcyc.cpp: In function 'int main()':
indcyc.cpp:104:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
indcyc.cpp:106:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", U+i, V+i);
   ~~~~~^~~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 764 KB Output is correct
2 Correct 2 ms 760 KB Output is correct
3 Correct 2 ms 764 KB Output is correct
4 Correct 2 ms 760 KB Output is correct
5 Correct 2 ms 376 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 760 KB Output is correct

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 760 KB Expected integer, but "no" found
2 Halted 0 ms 0 KB -

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 760 KB Output is correct

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 11 ms 760 KB Expected integer, but "no" found
2 Halted 0 ms 0 KB -

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 54 ms 916 KB Output is correct
2 Correct 5 ms 944 KB Output is correct
3 Correct 8 ms 888 KB Output is correct
4 Correct 58 ms 888 KB Output is correct

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 30 ms 888 KB Expected integer, but "no" found
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 113 ms 2040 KB Output is correct
2 Correct 39 ms 1528 KB Output is correct
3 Execution timed out 1055 ms 2040 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 364 ms 1400 KB Expected integer, but "no" found
2 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1073 ms 3192 KB Time limit exceeded
2 Halted 0 ms 0 KB -