oj.uz

답안 #54806

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
54806 2018-07-05T06:39:07 Z 윤교준(#1510) Pipes (CEOI15_pipes) C++11
100 / 100
 1217 ms 12436 KB 
#include <bits/stdc++.h>
#define pb push_back
#define eb emplace_back
#define sz(V) ((int)(V).size())
#define allv(V) ((V).begin()),((V).end())
#define befv(V) ((V)[sz(V)-2])
#define sorv(V) sort(allv(V))
#define revv(V) reverse(allv(V))
#define univ(V) (V).erase(unique(allv(V)),(V).end())
#define upmax(a,b) (a)=max((a),(b))
#define upmin(a,b) (a)=min((a),(b))
#define rb(x) ((x)&(-(x)))
#define INF (0x3f3f3f3f)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

struct DJF {
	DJF() { init(); }
	int ud[100001];
	void init() { iota(ud, ud+100001, 0); }
	int uf(int i) { return i == ud[i] ? i : (ud[i] = uf(ud[i])); }
	void uf(int a, int b) { ud[uf(b)] = uf(a); }
} djf1, djf2;

int GE[100001], GD[300005], GI[300005], Gn = 100001;

int EA[100001], EB[100001], En;

int prt[100001][17], dep[100001];
int cnt[2][100001];
bitset<100001> chk;

int N, M;

int lca(int a, int b) {
	if(dep[a] > dep[b]) swap(a, b);
	const int dt = dep[b] - dep[a];
	for(int i = 0; i < 17; i++) if(dt & (1<<i))
		b = prt[b][i];
	if(a == b) return a;
	for(int i = 16; ~i; i--) if(prt[a][i] != prt[b][i]) {
		a = prt[a][i]; b = prt[b][i];
	}
	return prt[a][0];
}

void f(int i) {
	for(int gi = i, v;;) {
		v = GD[gi];
		if(!v || !gi || gi == GE[i]) break;
		if(!dep[v]) {
            prt[v][0] = i;
            dep[v] = dep[i] + 1;
            f(v);
		}
		gi = GI[gi];
	}
}
void g(int i) {
	for(int gi = i, v;;) {
		v = GD[gi];
		if(!v || !gi || gi == GE[i]) break;
		if(dep[i] < dep[v]) {
            g(v);
            cnt[1][i] += cnt[1][v];
		}
		gi = GI[gi];
	}
    cnt[1][i] -= cnt[0][i];
    chk[i] = !!cnt[1][i];
}

int main() {
	//freopen("input.txt", "r", stdin);
	ios::sync_with_stdio(false); cin.tie(0);

    cin >> N >> M;
	iota(GE, GE+N+1, 0);

	for(int i = 0, a, b; i < M; i++) {
		cin >> a >> b;

		if(djf1.uf(a) == djf1.uf(b)) {
			if(djf2.uf(a) == djf2.uf(b)) continue;
			djf2.uf(a, b);
			En++;
			EA[En] = a; EB[En] = b;
			continue;
		}

		djf1.uf(a, b);
		{
			GD[GE[a]] = b;
			GI[GE[a]] = Gn;
			GE[a] = Gn;
			Gn++;
		}
		{
			GD[GE[b]] = a;
			GI[GE[b]] = Gn;
			GE[b] = Gn;
			Gn++;
		}
	}

	for(int i = 1; i <= N; i++) {
		if(dep[i]) continue;
		dep[i] = 1;
		f(i);
	}

	for(int j = 1; j < 17; j++) for(int i = 1; i <= N; i++)
		prt[i][j] = prt[prt[i][j-1]][j-1];

	for(int i = 1, a, b, c; i <= En; i++) {
		a = EA[i]; b = EB[i];
		c = lca(a, b);
		if(a == c) {
			cnt[0][a]++;
			cnt[1][b]++;
		} else {
			cnt[0][c] += 2;
			cnt[1][a]++;
			cnt[1][b]++;
		}
	}

	chk.reset();

	for(int i = 1; i <= N; i++) if(1 == dep[i]) g(i);
	for(int i = 1; i <= N; i++) if(1 < dep[i] && !chk[i])
		printf("%d %d\n", i, prt[i][0]);
	return 0;
}

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 1152 KB Output is correct
2 Correct 3 ms 1152 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 1664 KB Output is correct
2 Correct 6 ms 1664 KB Output is correct

Subtask #3
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 89 ms 1568 KB Output is correct
2 Correct 94 ms 1564 KB Output is correct

Subtask #4
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 188 ms 2300 KB Output is correct
2 Correct 202 ms 2296 KB Output is correct

Subtask #5
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 276 ms 3812 KB Output is correct
2 Correct 255 ms 4444 KB Output is correct

Subtask #6
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 411 ms 9016 KB Output is correct
2 Correct 401 ms 9016 KB Output is correct

Subtask #7
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 654 ms 10388 KB Output is correct
2 Correct 633 ms 9848 KB Output is correct

Subtask #8
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 830 ms 12280 KB Output is correct
2 Correct 749 ms 12436 KB Output is correct

Subtask #9
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 974 ms 12384 KB Output is correct
2 Correct 943 ms 12360 KB Output is correct

Subtask #10
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1211 ms 11776 KB Output is correct
2 Correct 1217 ms 12280 KB Output is correct