結果
問題 | No.1075 木の上の山 |
ユーザー |
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提出日時 | 2020-06-05 22:14:44 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
TLE
(最新)
AC
(最初)
|
実行時間 | - |
コード長 | 3,708 bytes |
コンパイル時間 | 3,126 ms |
コンパイル使用メモリ | 225,544 KB |
最終ジャッジ日時 | 2025-01-10 22:39:42 |
ジャッジサーバーID (参考情報) |
judge1 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 28 TLE * 2 |
ソースコード
#include <bits/stdc++.h>using namespace std;template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}using Int = long long;const char newl = '\n';template<typename T,T MOD = 1000000007>struct Mint{static constexpr T mod = MOD;T v;Mint():v(0){}Mint(signed v):v(v){}Mint(long long t){v=t%MOD;if(v<0) v+=MOD;}Mint pow(long long k){Mint res(1),tmp(v);while(k){if(k&1) res*=tmp;tmp*=tmp;k>>=1;}return res;}static Mint add_identity(){return Mint(0);}static Mint mul_identity(){return Mint(1);}Mint inv(){return pow(MOD-2);}Mint& operator+=(Mint a){v+=a.v;if(v>=MOD)v-=MOD;return *this;}Mint& operator-=(Mint a){v+=MOD-a.v;if(v>=MOD)v-=MOD;return *this;}Mint& operator*=(Mint a){v=1LL*v*a.v%MOD;return *this;}Mint& operator/=(Mint a){return (*this)*=a.inv();}Mint operator+(Mint a) const{return Mint(v)+=a;}Mint operator-(Mint a) const{return Mint(v)-=a;}Mint operator*(Mint a) const{return Mint(v)*=a;}Mint operator/(Mint a) const{return Mint(v)/=a;}Mint operator-() const{return v?Mint(MOD-v):Mint(v);}bool operator==(const Mint a)const{return v==a.v;}bool operator!=(const Mint a)const{return v!=a.v;}bool operator <(const Mint a)const{return v <a.v;}static Mint comb(long long n,int k){Mint num(1),dom(1);for(int i=0;i<k;i++){num*=Mint(n-i);dom*=Mint(i+1);}return num/dom;}};template<typename T,T MOD> constexpr T Mint<T, MOD>::mod;template<typename T,T MOD>ostream& operator<<(ostream &os,Mint<T, MOD> m){os<<m.v;return os;}template<typename V>V compress(V vs){sort(vs.begin(),vs.end());vs.erase(unique(vs.begin(),vs.end()),vs.end());return vs;}template<typename T>map<T, int> dict(const vector<T> &vs){map<T, int> res;for(int i=0;i<(int)vs.size();i++)res[vs[i]]=i;return res;}map<char, int> dict(const string &s){return dict(vector<char>(s.begin(),s.end()));}template<typename F>struct FixPoint : F{FixPoint(F&& f):F(forward<F>(f)){}template<typename... Args>decltype(auto) operator()(Args&&... args) const{return F::operator()(*this,forward<Args>(args)...);}};template<typename F>inline decltype(auto) MFP(F&& f){return FixPoint<F>{forward<F>(f)};}//INSERT ABOVE HEREsigned main(){cin.tie(0);ios::sync_with_stdio(0);int n,k;cin>>n>>k;vector<vector<int>> G(n);using P = pair<int, int>;vector<P> vp;for(int i=1;i<n;i++){int a,b;cin>>a>>b;a--;b--;G[a].emplace_back(b);G[b].emplace_back(a);vp.emplace_back(a,b);vp.emplace_back(b,a);}for(int i=0;i<n;i++)vp.emplace_back(i,-1);vp=compress(vp);auto dc=dict(vp);using M = Mint<int>;vector<vector<M>> dp(dc.size());// [0, i]vector<vector<M>> sm(dc.size());auto pre=MFP([&](auto dfs,int v,int p)->void{int idx=dc[P(v,p)];if(!dp[idx].empty()) return;dp[idx].assign(k,M(1));for(int u:G[v]){if(u==p) continue;dfs(u,v);int idy=dc[P(u,v)];for(int i=0;i<k;i++)dp[idx][i]*=sm[idy][i];}sm[idx]=dp[idx];for(int i=1;i<k;i++)sm[idx][i]+=sm[idx][i-1];});for(int i=0;i<n;i++) pre(i,-1);M ans{0};MFP([&](auto dfs,int v,int p)->void{for(int u:G[v]){if(u==p) continue;dfs(u,v);}int idx=dc[P(v,p)];if(p<0){for(int i=0;i<k;i++)ans+=dp[idx][i];}else{for(int i=1;i<k;i++)ans+=dp[idx][i]*sm[dc[P(p,v)]][i-1];}})(0,-1);cout<<ans<<newl;return 0;}