結果
問題 | No.2337 Equidistant |
ユーザー |
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提出日時 | 2023-06-02 22:35:18 |
言語 | C++11 (gcc 13.3.0) |
結果 |
AC
|
実行時間 | 1,937 ms / 4,000 ms |
コード長 | 11,580 bytes |
コンパイル時間 | 2,887 ms |
コンパイル使用メモリ | 130,016 KB |
実行使用メモリ | 66,304 KB |
最終ジャッジ日時 | 2024-12-28 20:14:54 |
合計ジャッジ時間 | 18,638 ms |
ジャッジサーバーID (参考情報) |
judge4 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 1 |
other | AC * 28 |
ソースコード
#include <iostream>#include <iomanip>#include <cstdio>#include <cmath>#include <ctime>#include <cstdlib>#include <cassert>#include <vector>#include <list>#include <stack>#include <queue>#include <deque>#include <map>#include <set>#include <bitset>#include <string>#include <algorithm>#include <utility>#include <complex>#include <array>#include <unordered_set>#include <unordered_map>#define rep(x, s, t) for(ll x = (s); (x) <= (t); (x)++)#define per(x, s, t) for(ll x = (s); (x) >= (t); (x)--)#define reps(x, s) for(ll x = 0; (x) < (ll)(s).size(); (x)++)#define pers(x, s) for(ll x = (ll)(s).size()-1; (x) >= 0; (x)--)#define chmin(x, y) (x) = min((x), (y))#define chmax(x, y) (x) = max((x), (y))#define sz(x) ((ll)(x).size())#define all(x) (x).begin(),(x).end()#define rall(x) (x).rbegin(),(x).rend()#define outl(...) dump_func(__VA_ARGS__)#define outf(x) cout << fixed << setprecision(16) << (x) << endl#define pb push_back#define fi first#define se second#define inf 2e18#define eps 1e-9const double PI = 3.1415926535897932384626433;using namespace std;typedef long long ll;typedef unsigned long long ull;typedef pair<ll, ll> P;struct edge{ll to, cost;edge(){}edge(ll a, ll b){ to = a, cost = b;}};const int dx[] = {1, 0, -1, 0}, dy[] = {0, -1, 0, 1};const int dx8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dy8[] = {0, -1, -1, -1, 0, 1, 1, 1};const int mod = 998244353;//const int mod = 1000000007;struct mint{int x;mint(ll y = 0){if(y < 0 || y >= mod) y = (y%mod+mod)%mod; x = y;}mint(const mint &ope) {x = ope.x;}mint operator-(){return mint(-x);}mint operator+(const mint &ope){return mint(x) += ope;}mint operator-(const mint &ope){return mint(x) -= ope;}mint operator*(const mint &ope){return mint(x) *= ope;}mint operator/(const mint &ope){return mint(x) /= ope;}mint& operator+=(const mint &ope){x += ope.x; if(x >= mod) x -= mod; return *this;}mint& operator-=(const mint &ope){x += mod - ope.x; if(x >= mod) x -= mod; return *this;}mint& operator*=(const mint &ope){ll tmp = x; tmp *= ope.x, tmp %= mod; x = tmp; return *this;}mint& operator/=(const mint &ope){ll n = mod-2; mint mul = ope;while(n){if(n & 1) *this *= mul; mul *= mul; n >>= 1;}return *this;}mint inverse(){return mint(1) / *this;}bool operator ==(const mint &ope){return x == ope.x;}bool operator !=(const mint &ope){return x != ope.x;}bool operator <(const mint &ope)const{return x < ope.x;}};mint modpow(mint a, ll n){if(n == 0) return mint(1);if(n % 2) return a * modpow(a, n-1);else return modpow(a*a, n/2);}istream& operator >>(istream &is, mint &ope){ll t; is >> t, ope = mint(t); return is;}ostream& operator <<(ostream &os, mint &ope){return os << ope.x;}ostream& operator <<(ostream &os, const mint &ope){return os << ope.x;}ll modpow(ll a, ll n, ll mod){if(n == 0) return 1;if(n % 2) return ((a%mod) * (modpow(a, n-1, mod)%mod)) % mod;else return modpow((a*a)%mod, n/2, mod) % mod;}vector<mint> fact, fact_inv;void make_fact(int n){fact.resize(n+1), fact_inv.resize(n+1);fact[0] = mint(1); rep(i, 1, n) fact[i] = fact[i-1] * mint(i);fact_inv[n] = fact[n].inverse(); per(i, n-1, 0) fact_inv[i] = fact_inv[i+1] * mint(i+1);}mint comb(int n, int k){ if(n < 0 || k < 0 || n < k) return mint(0); return fact[n] * fact_inv[k] * fact_inv[n-k];}mint perm(int n, int k){ return comb(n, k) * fact[k]; }mint divide(int n, int k){ return comb(n+k-1, k-1); }template<typename T> T comb2(ll n, ll k){ if(n < 0 || k < 0 || n < k) return T(0); T ret = 1; rep(i, 1, k) ret *= n-k+i, ret /= i; return ret;}vector<ll> prime, pvec, qrime;void make_prime(int n){prime.resize(n+1);rep(i, 2, n){if(prime[i] == 0) pvec.push_back(i), prime[i] = i;for(auto p : pvec){ if(i*p > n || p > prime[i]) break; prime[i*p] = p;}}}void make_qrime(int n){qrime.resize(n+1);rep(i, 2, n){int ni = i / prime[i]; if(prime[i] == prime[ni]) qrime[i] = qrime[ni] * prime[i]; else qrime[i] = prime[i];}}void factorize(ll n, map<ll, ll> &mp){mp.clear();for(auto p : pvec) while(n % p == 0) mp[p]++, n /= p;if(n > 1) mp[n]++;}bool exceed(ll x, ll y, ll m){return y > 0 && x >= m / y + 1;}void mark(){ cout << "*" << endl; }void yes(){ cout << "Yes" << endl; }void no(){ cout << "No" << endl; }ll floor(ll a, ll b){ if(b < 0) a *= -1, b *= -1; if(a >= 0) return a/b; else return -((-a+b-1)/b); }ll ceil(ll a, ll b){ if(b < 0) a *= -1, b *= -1; if(a >= 0) return (a+b-1)/b; else return -((-a)/b); }ll modulo(ll a, ll b){ b = abs(b); return a - floor(a, b) * b;}ll sgn(ll x){ if(x > 0) return 1; if(x < 0) return -1; return 0;}ll gcd(ll a, ll b){if(b == 0) return a; return gcd(b, a%b);}ll lcm(ll a, ll b){return a/gcd(a, b)*b;}template<typename T> T arith(T x){return x*(x+1)/2;}template<typename T> T arith2(T x){return x*(x+1)*(x*2+1)/6;}ll digitnum(ll x, ll b = 10){ll ret = 0; for(; x; x /= b) ret++; return ret;}ll digitsum(ll x, ll b = 10){ll ret = 0; for(; x; x /= b) ret += x % b; return ret;}string lltos(ll x, ll b = 10){if(x == 0) return "0"; string ret; for(;x;x/=b) ret += x % b + '0'; reverse(all(ret)); return ret;}ll stoll(string &s, ll b = 10){ll ret = 0; for(auto c : s) ret *= b, ret += c - '0'; return ret;}template<typename T> void uniq(T &vec){sort(all(vec)); vec.erase(unique(all(vec)), vec.end());}int popcount(ull x){x -= ((x>>1)&0x5555555555555555ULL), x = (x & 0x3333333333333333ULL) + ((x>>2) & 0x3333333333333333ULL);return (((x + (x>>4)) & 0x0F0F0F0F0F0F0F0FULL) * 0x0101010101010101ULL) >> 56;}template<typename T> vector<pair<T, ll>> rle(vector<T> vec){vector<pair<T, ll>> ret;for(auto x : vec){if(sz(ret) == 0 || ret.back().first != x) ret.push_back(P(x, 1)); else ret.back().second++;}return ret;}vector<pair<char, ll>> rle(string s){ vector<char> vec; for(auto c : s) vec.push_back(c); return rle(vec);}template<class S, class T> pair<S, T>& operator+=(pair<S, T> &s, const pair<S, T> &t){s.first += t.first, s.second += t.second; return s;}template<class S, class T> pair<S, T>& operator-=(pair<S, T> &s, const pair<S, T> &t){s.first -= t.first, s.second -= t.second; return s;}template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t){return pair<S,T>(s.first+t.first, s.second+t.second);}template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t){return pair<S,T>(s.first-t.first, s.second-t.second);}template<class T> T dot(const pair<T, T> &s, const pair<T, T> &t){return s.first*t.first + s.second*t.second;}template<class T> T cross(const pair<T, T> &s, const pair<T, T> &t){return s.first*t.second - s.second*t.first;}template<class T> T mdist(pair<T, T> s, pair<T, T> t){return abs(s.first-t.first) + abs(s.second-t.second);}template<class T> T cdist(pair<T, T> s, pair<T, T> t){return max(abs(s.first-t.first), abs(s.second-t.second));}template<class T> T edist2(pair<T, T> s, pair<T, T> t){return (s.first-t.first)*(s.first-t.first) + (s.second-t.second)*(s.second-t.second);}template<typename T> ostream& operator << (ostream& os, vector<T>& vec){reps(i, vec) os << vec[i] << " "; return os;}template<typename T> ostream& operator << (ostream& os, const vector<T>& vec){reps(i, vec) os << vec[i] << " "; return os;}template<typename T> ostream& operator << (ostream& os, list<T>& ls){for(auto x : ls) os << x << " "; return os;}template<typename T> ostream& operator << (ostream& os, const list<T>& ls){for(auto x : ls) os << x << " "; return os;}template<typename T> ostream& operator << (ostream& os, deque<T>& deq){reps(i, deq) os << deq[i] << " "; return os;}template<typename T, typename U> ostream& operator << (ostream& os, pair<T, U>& ope){ os << "(" << ope.first << ", " << ope.second << ")"; return os;}template<typename T, typename U> ostream& operator << (ostream& os, const pair<T, U>& ope){ os << "(" << ope.first << ", " << ope.second << ")";return os;}template<typename T, typename U> ostream& operator << (ostream& os, map<T, U>& ope){ for(auto p : ope) os << "(" << p.first << ", " << p.second << "),";return os;}template<typename T> ostream& operator << (ostream& os, set<T>& ope){for(auto x : ope) os << x << " "; return os;}template<typename T> ostream& operator << (ostream& os, multiset<T>& ope){for(auto x : ope) os << x << " "; return os;}template<typename T> void outa(T a[], ll s, ll t){rep(i, s, t){ cout << a[i]; if(i < t) cout << " ";} cout << endl;}template<typename T, size_t N> ostream& operator << (ostream& os, array<T, N>& arr){reps(i, arr) os << arr[i] << " "; return os;}template<typename T, size_t N> ostream& operator << (ostream& os, const array<T, N>& arr){reps(i, arr) os << arr[i] << " "; return os;}void dump_func(){cout << endl;}template <class Head, class... Tail>void dump_func(Head &&head, Tail &&... tail){cout << head; if(sizeof...(Tail) > 0) cout << " "; dump_func(std::move(tail)...);}template<typename T> void bssert(bool b, T t){ if(!b) cout << t << endl, exit(0); }struct LCA{struct edge{int to; ll cost;edge(){}edge(int a, int b){to = a, cost = b;}};int n, logn;vector<vector<edge> > G;vector<vector<int> > prev;vector<int> depth;vector<ll> dist;LCA(){}LCA(int n){init(n);}void init(int n){this->n = n;G.clear(), G.resize(n+1);}void add_edge(int u, int v, ll w = 1){G[u].push_back(edge(v, w));G[v].push_back(edge(u, w));}void predfs(int v, int p, int d, ll l){prev[v][0] = p, depth[v] = d, dist[v] = l;for(auto e : G[v]){if(e.to == p) continue;predfs(e.to, v, d+1, l+e.cost);}}void calc(int root = 1){logn = 0;for(int i = 0; ; i++) if(n <= (1<<i)){ logn = i; break; }chmax(logn, 1);prev.resize(n+1);for(int i = 0; i < prev.size(); i++) prev[i].resize(logn);depth.resize(n+1), dist.resize(n+1);prev[0][0] = 0;predfs(root, 0, 0, 0);for(int i = 1; i < logn; i++){for(int j = 0; j <= n; j++){prev[j][i] = prev[prev[j][i-1]][i-1];}}}int getLCA(int u, int v){int x = u, y = v;if(depth[y] > depth[x]) swap(x, y);for(int i = logn-1; i >= 0; i--){if(depth[x] - (1<<i) >= depth[y]) x = prev[x][i];}if(x == y) return x;for(int i = logn-1; i >= 0; i--){if(prev[x][i] != prev[y][i]){x = prev[x][i], y = prev[y][i];}}x = prev[x][0];return x;}ll getDist(int u, int v){return dist[u]+dist[v]-dist[getLCA(u, v)]*2;}int getAncestor(int v, int k){for(int i = 0; i < logn; i++){if(k & (1<<i)) v = prev[v][i];}return v;}int getNext(int u, int v){if(u == v) return -1;if(getLCA(u, v) == u) return getAncestor(v, depth[v]-depth[u]-1);else return prev[u][0];}};ll n, Q;vector<ll> G[200005];ll sub[200005];void dfs(int v, int p){sub[v] = 1;for(auto u : G[v]){if(u == p) continue;dfs(u, v);sub[v] += sub[u];}}int main(void){ios::sync_with_stdio(0);cin.tie(0);cin >> n >> Q;LCA lca(n);ll u, v;rep(i, 1, n-1){cin >> u >> v;lca.add_edge(u, v);G[u].pb(v);G[v].pb(u);}dfs(1, -1);lca.calc();rep(i, 1, Q){cin >> u >> v;ll d = lca.getDist(u, v);if(d % 2){cout << 0 << "\n";continue;}d /= 2;ll l = lca.getLCA(u, v), m;if(lca.depth[u]-lca.depth[l] > lca.depth[v]-lca.depth[l]) m = lca.getAncestor(u, d);else m = lca.getAncestor(v, d);u = lca.getNext(m, u), v = lca.getNext(m, v);ll ans = sub[m];if(lca.depth[u] > lca.depth[m]) ans -= sub[u];if(lca.depth[v] > lca.depth[m]) ans -= sub[v];if(m == l) ans += sub[1] - sub[l];cout << ans << "\n";}return 0;}