結果
| 問題 |
No.2704 L to R Graph
|
| コンテスト | |
| ユーザー |
 woodywoody
|
| 提出日時 | 2024-03-30 19:42:45 |
| 言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 502 ms / 3,000 ms |
| コード長 | 10,534 bytes |
| コンパイル時間 | 4,570 ms |
| コンパイル使用メモリ | 247,336 KB |
| 実行使用メモリ | 37,212 KB |
| 最終ジャッジ日時 | 2024-09-30 17:44:00 |
| 合計ジャッジ時間 | 12,347 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge4 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 26 |
ソースコード
#include<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,b) for(int i=0;i<b;i++)
#define rrep(i,b) for(int i=b-1;i>=0;i--)
#define rep1(i,b) for(int i=1;i<b;i++)
#define repx(i,x,b) for(int i=x;i<b;i++)
#define rrepx(i,x,b) for(int i=b-1;i>=x;i--)
#define fore(i,a) for(auto& i:a)
#define rng(x) (x).begin(), (x).end()
#define rrng(x) (x).rbegin(), (x).rend()
#define sz(x) ((int)(x).size())
#define pb push_back
#define fi first
#define se second
#define pcnt __builtin_popcountll
using namespace std;
using namespace atcoder;
using ll = long long;
using ull = long long;
using ld = long double;
template<typename T> using mpq = priority_queue<T, vector<T>, greater<T>>;
template<typename T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<typename T> bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<typename T> ll sumv(const vector<T>&a){ll res(0);for(auto&&x:a)res+=x;return res;}
bool yn(bool a) { if(a) {cout << "Yes" << endl; return true;} else {cout << "No" << endl; return false;}}
#define retval(x) {cout << #x << endl; return;}
#define cout2(x,y) cout << x << " " << y << endl;
#define coutp(p) cout << p.fi << " " << p.se << endl;
#define out cout << ans << endl;
#define outd cout << fixed << setprecision(20) << ans << endl;
#define outm cout << ans.val() << endl;
#define outv fore(yans , ans) cout << yans << "\n";
#define outdv fore(yans , ans) cout << yans.val() << "\n";
#define assertmle(x) if (!(x)) {vi v(3e8);}
#define asserttle(x) if (!(x)) {while(1){}}
#define coutv(v) {fore(vy , v) {cout << vy << " ";} cout << endl;}
#define coutv2(v) fore(vy , v) cout << vy << "\n";
#define coutvm(v) {fore(vy , v) {cout << vy.val() << " ";} cout << endl;}
#define coutvm2(v) fore(vy , v) cout << vy.val() << "\n";
using pll = pair<ll,ll>;using pil = pair<int,ll>;using pli = pair<ll,int>;using pii = pair<int,int>;using pdd = pair<ld,ld>;
using vi = vector<int>;using vd = vector<ld>;using vl = vector<ll>;using vs = vector<string>;using vb = vector<bool>;
using vpii = vector<pii>;using vpli = vector<pli>;using vpll = vector<pll>;using vpil = vector<pil>;
using vvi = vector<vector<int>>;using vvl = vector<vector<ll>>;using vvs = vector<vector<string>>;using vvb = vector<vector<bool>>;
using vvpii = vector<vector<pii>>;using vvpli = vector<vector<pli>>;using vvpll = vector<vpll>;using vvpil = vector<vpil>;
using mint = modint998244353;
//using mint = modint1000000007;
//using mint = dynamic_modint<0>;
using vm = vector<mint>;
using vvm = vector<vector<mint>>;
vector<int> dx={1,0,-1,0,1,1,-1,-1},dy={0,1,0,-1,1,-1,1,-1};
ll gcd(ll a, ll b) { return a?gcd(b%a,a):b;}
ll lcm(ll a, ll b) { return a/gcd(a,b)*b;}
#define yes {cout <<"Yes"<<endl;}
#define no {cout <<"No"<<endl;}
const double eps = 1e-10;
const ll LINF = 2001002003004005006ll;
const int INF = 1001001001;
#ifdef MY_LOCAL_DEBUG
#include "./debug/localDebug.cpp"
#define showp(p) cerr<<#p<<" = "<<p.fi<<" : "<<p.se<<endl
#define show1(a) cerr<<#a<<" = "<<a<<endl
#define show2(a,b) cerr<<#a<<" = "<<a<<" : "<<#b<<" = "<<b<<endl
#define show3(a,b,c) cerr<<#a<<" = "<<a<<" : "<<#b<<" = "<<b<<" : "<<#c<<" = "<<c<<endl
#define show4(a,b,c,d) cerr<<#a<<" = "<<a<<" : "<<#b<<" = "<<b<<" : "<<#c<<" = "<<c<<" : "<<#d<<" = "<<d<<endl
#define show5(a,b,c,d,e) cerr<<#a<<" = "<<a<<" : "<<#b<<" = "<<b<<" : "<<#c<<" = "<<c<<" : "<<#d<<" = "<<d<<" : "<<#e<<" = "<<e<<endl
#define DEBUG_LINE cout << "DEBUG_LINE : " << __LINE__ << endl
#define showv(v) {cout<<#v<<" : "; fore(vy , v) {cout << vy << " ";} cout << endl;}
#define showv2(v) {cout<<#v<<endl; fore(vy , v) cout << vy << "\n";}
#define showvm(v) {cout<<#v<<" : "; fore(vy , v) {cout << vy.val() << " ";} cout << endl;}
#define showvm2(v) {cout<<#v<<endl; fore(vy , v) cout << vy.val() << "\n";}
#define showmat(v) {cout<<#v<<endl; fore(row , v) { fore(seg , row) cout << seg << " "; cout << endl;}}
#define showmatm(v) {cout<<#v<<endl; fore(row , v) { fore(seg , row) cout << seg.val() << " "; cout << endl;}}
#else
#define showp(p)
#define show1(a)
#define show2(a,b)
#define show3(a,b,c)
#define show4(a,b,c,d)
#define show5(a,b,c,d,e)
#define DEBUG_LINE
#define showv(v)
#define showv2(v)
#define showvm(v)
#define showvm2(v)
#define showmat(v)
#define showmatm(v)
#endif
#define overload5(a,b,c,d,e,f, ...) f
#define show(...) overload5(__VA_ARGS__, show5, show4, show3, show2, show1)(__VA_ARGS__)
template<typename T>
struct LCA {
int n, root, l;
vector<vector<int>> to;
vector<vector<T>> co;
vector<int> dep;
vector<T> costs;
vector<vector<int>> par;
dsu d;
vi r;
LCA(int n):n(n),to(n),co(n),dep(n),costs(n) {
l = 0;
while ((1<<l) < n) ++l;
par = vector<vector<int>>(n+1,vector<int>(l,n));
d = dsu(n);
r = vi(n,-1);
}
void add_edge(int a, int b, T c=1) {
if (a==b) return;
to[a].push_back(b); co[a].push_back(c);
to[b].push_back(a); co[b].push_back(c);
if (a!=n && b!=n){
d.merge(a,b);
}
}
// par[x][0],dep,costsを計算
void _dfs(int v, int d=0, T c=0, int p=-1, int now=-1) {
if (p != -1) par[v][0] = p;
if (now==-1 && v!=root) now = v;
r[v] = now;
dep[v] = d;
costs[v] = c;
for (int i = 0; i < sz(to[v]); ++i) {
int u = to[v][i];
if (u == p) continue;
_dfs(u, d+1, c+co[v][i], v, now);
}
}
void init(int _root=0) {
root = _root;
_dfs(root);
for (int i = 0; i < l-1; ++i) {
for (int v = 0; v < n; ++v) {
par[v][i+1] = par[par[v][i]][i];
}
}
}
int lca(int a,int b){
if (!d.same(a,b)) return -1;
if (dep[a] > dep[b]) swap(a,b);
int gap = dep[b]-dep[a];
for (int i = l-1; i >= 0; --i) {
int len = 1<<i;
if (gap >= len) {
gap -= len;
b = par[b][i];
}
}
if (a == b) return a;
for (int i = l-1; i >= 0; --i) {
int na = par[a][i];
int nb = par[b][i];
if (na != nb) a = na, b = nb;
}
return par[a][0];
}
int getPar(int x,int k){
int now = x;
rrep(i,30){
if ((k >> i & 1) == 1){
now = par[now][i];
}
}
return now;
}
int length(int a, int b) {
if (!d.same(a,b)) return -1;
int c = lca(a,b);
return dep[a]+dep[b]-dep[c]*2;
}
T dist(int a, int b) {
int c = lca(a,b);
return costs[a]+costs[b]-costs[c]*2;
}
};
// 初期化方法 LCA<T> g(n) : nは頂点数、Tはコストのタイプ、注) 宣言 → add_edge → init の順で呼び出す
// add_edge(a,b,c) : a,b間にコストcの辺をはる。cは省略可(1となる)。
// init() : ダブリングにより各頂点の2^i個上の親を計算。結果はpar[v][i]に入る。
// lca(a,b) : 頂点a,bのlcaを出力。
// getPar(x,k) : 頂点xの2^k上の祖先を出力。
// length(a,b) : 頂点a,b間の辺の数を出力。
// dist(a,b) : 頂点a,b間のコストを出力。
void solve(){
int n,l,r; cin>>n>>l>>r;
vi a(n); rep(i,n) cin>>a[i],a[i]--;
vi d(n);
vvi e(n);
dsu ds(n);
rep(i,n){
d[a[i]]++;
e[i].pb(a[i]);
ds.merge(i, a[i]);
}
queue<int> q;
rep(i,n) if (d[i]==0) q.push(i);
vb flg(n,true);
while(sz(q)){
int p = q.front();
q.pop();
flg[p] = false;
fore(y , e[p]){
if (--d[y]==0) q.push(y);
}
}
int root = n;
LCA<int> lc(n+1);
rep(i,n){
if (flg[i]){
lc.add_edge(i, root);
continue;
}
fore(y , e[i]){
lc.add_edge(i, y);
}
}
lc.init(root);
vvi loop;
vb flg2(n);
vi id(n,-1);
vi id_loop(n,-1);
rep(i,n){
if (!flg[i]) continue;
if (flg2[i]) continue;
int x = a[i];
vi v = {i};
flg2[i] = true;
while(x != i){
v.pb(x);
flg2[x] = true;
x = a[x];
}
rep(j,sz(v)){
id[v[j]] = j;
id_loop[v[j]] = sz(loop);
}
loop.pb(v);
}
auto get_loop_size = [&](int i)->int{
assertmle(flg[i]);
return sz(loop[id_loop[i]]);
};
// 同じループにある頂点通しの距離
auto get_loop_dist = [&](int a,int b)->int{
asserttle(flg[a]);
asserttle(flg[b]);
asserttle(ds.same(a,b));
int ret;
int ai = id[a];
int bi = id[b];
if (ai <= bi) ret = bi-ai;
else{
ret = get_loop_size(a) - (ai-bi);
}
return ret;
};
auto get_dist = [&](int a,int b)->int{
if (!ds.same(a,b)) return -1;
if (!flg[a] && !flg[b] && !lc.d.same(a,b)) return -1;
if (flg[a] && !flg[b]) return -1;
if (flg[a] && flg[b]){
return get_loop_dist(a,b);
}else if(!flg[a] && flg[b]){
int ar = lc.r[a];
return lc.dist(a,ar) + get_loop_dist(ar,b);
}else{
int c = lc.lca(a,b);
if (c==b) return lc.dist(a,b);
else return -1;
}
};
int qi; cin>>qi;
vi ans(qi,-1);
rep(i,qi){
int a,b; cin>>a>>b;
a--; b--;
int dist = get_dist(a,b);
if (dist==-1) continue;
if (!flg[b]){
int k = (dist+r-1)/r;
if (k*l <= dist) ans[i] = k;
continue;
}
ll d1 = dist;
ll d2 = get_loop_size(b);
auto get_sum = [&](ll x, ll cnt, bool isR)->ll{
if (x==0) return 0;
ll lower = (d1+!isR+x-1)/x;
if (lower > cnt) return 0;
ll ret = floor_sum(cnt+1,d2,x,(d2-d1-!isR));
// assert(ret>=0);
ret -= floor_sum(lower,d2,x,(d2-d1-!isR));
return ret;
};
auto check = [&](ll mid)->bool{
return (get_sum(r,mid,true)==get_sum(l,mid,false));
};
ll li=0,ui=n+1;
if (check(ui)) continue;
while(ui-li>1){
ll mid = (li+ui)/2;
if (check(mid)) li = mid;
else ui = mid;
}
ans[i] = ui;
}
outv;
return;
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
int t = 1;
//cin>>t;
rep(i,t){
solve();
}
return 0;
}