結果
| 問題 |
No.2464 To DAG
|
| コンテスト | |
| ユーザー |
 hos.lyric
|
| 提出日時 | 2023-09-08 22:31:38 |
| 言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
WA
|
| 実行時間 | - |
| コード長 | 8,376 bytes |
| コンパイル時間 | 1,396 ms |
| コンパイル使用メモリ | 121,688 KB |
| 実行使用メモリ | 87,716 KB |
| 最終ジャッジ日時 | 2024-06-26 15:44:19 |
| 合計ジャッジ時間 | 15,942 ms |
|
ジャッジサーバーID （参考情報） |
judge4 / judge5 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 1 WA * 1 |
| other | AC * 18 WA * 21 |
ソースコード
#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using Int = long long;
template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")
struct HLD {
int n, rt;
// needs to be tree
// vertex lists
// modified in build(rt) (parent removed, heavy child first)
vector<vector<int>> graph;
vector<int> sz, par, dep;
int zeit;
vector<int> dis, fin, sid;
// head vertex (minimum depth) in heavy path
vector<int> head;
HLD() : n(0), rt(-1), zeit(0) {}
explicit HLD(int n_) : n(n_), rt(-1), graph(n), zeit(0) {}
void ae(int u, int v) {
assert(0 <= u); assert(u < n);
assert(0 <= v); assert(v < n);
graph[u].push_back(v);
graph[v].push_back(u);
}
void dfsSz(int u) {
sz[u] = 1;
for (const int v : graph[u]) {
auto it = std::find(graph[v].begin(), graph[v].end(), u);
if (it != graph[v].end()) graph[v].erase(it);
par[v] = u;
dep[v] = dep[u] + 1;
dfsSz(v);
sz[u] += sz[v];
}
}
void dfsHLD(int u) {
dis[u] = zeit++;
const int deg = graph[u].size();
if (deg > 0) {
int vm = graph[u][0];
int jm = 0;
for (int j = 1; j < deg; ++j) {
const int v = graph[u][j];
if (sz[vm] < sz[v]) {
vm = v;
jm = j;
}
}
swap(graph[u][0], graph[u][jm]);
head[vm] = head[u];
dfsHLD(vm);
for (int j = 1; j < deg; ++j) {
const int v = graph[u][j];
head[v] = v;
dfsHLD(v);
}
}
fin[u] = zeit;
}
void build(int rt_) {
assert(0 <= rt_); assert(rt_ < n);
rt = rt_;
sz.assign(n, 0);
par.assign(n, -1);
dep.assign(n, -1);
dep[rt] = 0;
dfsSz(rt);
zeit = 0;
dis.assign(n, -1);
fin.assign(n, -1);
head.assign(n, -1);
head[rt] = rt;
dfsHLD(rt);
assert(zeit == n);
sid.assign(n, -1);
for (int u = 0; u < n; ++u) sid[dis[u]] = u;
}
friend ostream &operator<<(ostream &os, const HLD &hld) {
const int maxDep = *max_element(hld.dep.begin(), hld.dep.end());
vector<string> ss(2 * maxDep + 1);
int pos = 0, maxPos = 0;
for (int j = 0; j < hld.n; ++j) {
const int u = hld.sid[j];
const int d = hld.dep[u];
if (hld.head[u] == u) {
if (j != 0) {
pos = maxPos + 1;
ss[2 * d - 1].resize(pos, '-');
ss[2 * d - 1] += '+';
}
} else {
ss[2 * d - 1].resize(pos, ' ');
ss[2 * d - 1] += '|';
}
ss[2 * d].resize(pos, ' ');
ss[2 * d] += std::to_string(u);
if (maxPos < static_cast<int>(ss[2 * d].size())) {
maxPos = ss[2 * d].size();
}
}
for (int d = 0; d <= 2 * maxDep; ++d) os << ss[d] << '\n';
return os;
}
bool contains(int u, int v) const {
return (dis[u] <= dis[v] && dis[v] < fin[u]);
}
int lca(int u, int v) const {
assert(0 <= u); assert(u < n);
assert(0 <= v); assert(v < n);
for (; head[u] != head[v]; ) (dis[u] > dis[v]) ? (u = par[head[u]]) : (v = par[head[v]]);
return (dis[u] > dis[v]) ? v : u;
}
int jumpUp(int u, int d) const {
assert(0 <= u); assert(u < n);
assert(d >= 0);
if (dep[u] < d) return -1;
const int tar = dep[u] - d;
for (u = head[u]; ; u = head[par[u]]) {
if (dep[u] <= tar) return sid[dis[u] + (tar - dep[u])];
}
}
int jump(int u, int v, int d) const {
assert(0 <= u); assert(u < n);
assert(0 <= v); assert(v < n);
assert(d >= 0);
const int l = lca(u, v);
const int du = dep[u] - dep[l], dv = dep[v] - dep[l];
if (d <= du) {
return jumpUp(u, d);
} else if (d <= du + dv) {
return jumpUp(v, du + dv - d);
} else {
return -1;
}
}
// [u, v) or [u, v]
template <class F> void doPathUp(int u, int v, bool inclusive, F f) const {
assert(contains(v, u));
for (; head[u] != head[v]; u = par[head[u]]) f(dis[head[u]], dis[u] + 1);
if (inclusive) {
f(dis[v], dis[u] + 1);
} else {
if (v != u) f(dis[v] + 1, dis[u] + 1);
}
}
// not path order, include lca(u, v) or not
template <class F> void doPath(int u, int v, bool inclusive, F f) const {
const int l = lca(u, v);
doPathUp(u, l, false, f);
doPathUp(v, l, inclusive, f);
}
// (vs, ps): compressed tree
// vs: DFS order (sorted by dis)
// vs[ps[x]]: the parent of vs[x]
// ids[vs[x]] = x, not set for non-tree vertex
vector<int> ids;
pair<vector<int>, vector<int>> compress(vector<int> us) {
// O(n) first time
ids.resize(n, -1);
std::sort(us.begin(), us.end(), [&](int u, int v) -> bool {
return (dis[u] < dis[v]);
});
us.erase(std::unique(us.begin(), us.end()), us.end());
int usLen = us.size();
assert(usLen >= 1);
for (int x = 1; x < usLen; ++x) us.push_back(lca(us[x - 1], us[x]));
std::sort(us.begin(), us.end(), [&](int u, int v) -> bool {
return (dis[u] < dis[v]);
});
us.erase(std::unique(us.begin(), us.end()), us.end());
usLen = us.size();
for (int x = 0; x < usLen; ++x) ids[us[x]] = x;
vector<int> ps(usLen, -1);
for (int x = 1; x < usLen; ++x) ps[x] = ids[lca(us[x - 1], us[x])];
return make_pair(us, ps);
}
};
////////////////////////////////////////////////////////////////////////////////
template <class T> void bAdd(vector<T> &bit, int pos, const T &val) {
const int bitN = bit.size();
for (int x = pos; x < bitN; x |= x + 1) bit[x] += val;
}
template <class T> T bSum(const vector<T> &bit, int pos) {
T ret = 0;
for (int x = pos; x > 0; x &= x - 1) ret += bit[x - 1];
return ret;
}
template <class T> T bSum(const vector<T> &bit, int pos0, int pos1) {
return bSum(bit, pos1) - bSum(bit, pos0);
}
int N, M;
vector<int> A, B;
vector<vector<int>> G;
vector<int> vis, on;
vector<int> pari;
void dfs(int u) {
vis[u] = 1;
for (const int i : G[u]) {
const int v = B[i];
if (!vis[v]) {
pari[v] = i;
on[i] = 1;
dfs(v);
}
}
}
int main() {
for (; ~scanf("%d%d", &N, &M); ) {
A.resize(M);
B.resize(M);
for (int i = 0; i < M; ++i) {
scanf("%d%d", &A[i], &B[i]);
--A[i];
--B[i];
}
G.assign(N, {});
for (int i = 0; i < M; ++i) {
G[A[i]].push_back(i);
}
vis.assign(N, 0);
pari.assign(N, -1);
on.assign(M, 0);
HLD hld(N + 1);
for (int u = 0; u < N; ++u) if (!vis[u]) {
hld.ae(N, u);
dfs(u);
}
for (int i = 0; i < M; ++i) if (on[i]) {
hld.ae(A[i], B[i]);
}
hld.build(N);
// cerr<<hld<<endl;
vector<int> bit(N, 0);
vector<int> del(M, 0);
for (int i = 0; i < M; ++i) if (!on[i]) {
if (hld.contains(B[i], A[i])) {
// cerr<<"back "<<A[i]<<" "<<B[i]<<endl;
int sum = 0;
hld.doPathUp(A[i], B[i], false, [&](int x, int y) -> void {
sum += bSum(bit, x, y);
});
if (sum == 0) {
del[i] = 1;
for (int v = A[i]; v != B[i]; v = hld.par[v]) {
del[pari[v]] = 1;
bAdd(bit, hld.dis[v], +1);
}
}
}
}
int ansCnt = 0;
for (int i = 0; i < M; ++i) if (!del[i]) {
++ansCnt;
}
printf("%d %d\n", N, ansCnt);
for (int i = 0; i < M; ++i) if (!del[i]) {
printf("%d %d\n", A[i] + 1, B[i] + 1);
}
cerr<<"========"<<endl;
}
return 0;
}