제출 #1310637

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1310637		thelegendary08	Janjetina (COCI21_janjetina)	C++17	110 / 110	450 ms	21132 KiB

Main

#include<bits/stdc++.h>
// #include<atcoder/modint>
// #include<atcoder/convolution>
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define F first
#define S second
#define rs resize
#define ft front()
#define bk back()
#define int long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int, int>
#define vpii vector<pair<int, int>>
#define vc vector<char>
#define vb vector<bool>
#define mii map<int,int>
#define f0r(i,n) for(int i=0;i<n;i++)
#define FOR(i,k,n) for(int i=k;i<n;i++)
#define r0f(i,n) for(int i = n-1; i >= 0; i--)
#define R0F(i,k,n) for(int i = n-1; i >= k; i--)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define SUM(v) (accumulate(all(v), 0LL))
#define in(a) int a; cin>>a
#define in2(a,b) int a,b; cin>>a>>b
#define in3(a,b,c) int a,b,c; cin>>a>>b>>c
#define in4(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d
#define vin(v,n); vi v(n); f0r(i,n){cin>>v[i];}
#define out(a) cout<<a<<'\n'
#define out2(a,b) cout<<a<<' '<<b<<'\n'
#define out3(a,b,c) cout<<a<<' '<<b<<' '<<c<<'\n'
#define out4(a,b,c,d) cout<<a<<' '<<b<<' '<<c<<' '<<d<<'\n'
#define pout(a) cout<<a.first<<' '<<a.second<<'\n'
#define vout(v) for(auto u : v){cout<<u<<' ';} cout<<endl
#define dout(a) cout<<a<<' '<<#a<<endl
#define dout2(a,b) cout<<a<<' '<<#a<<' '<<b<<' '<<#b<<endl
#define YN(x); if(x){cout<<"YES"<<'\n';}else{cout<<"NO"<<'\n';}
#define yn(x); if(x){cout<<"Yes"<<'\n';}else{cout<<"No"<<'\n';}
#define p2(x) (1LL << (x))
#define pct(x) (__builtin_popcountll((x)))
#define ist(x,y) (((x) >> (y)) & 1)
template<class T, class U> bool ckmin(T& a, const U& b) { return (T)b < a ? a = (T)b, 1 : 0; } 
template<class T, class U> bool ckmax(T& a, const U& b) { return a < (T)b ? a = (T)b, 1 : 0; } 
const int leg = 1e9 + 7;
const int mod = 998244353;
using namespace std;
// using namespace atcoder; 
// using mint = modint998244353;
// using mint = modint1000000007;
const int mxn = 1e5 + 5; 
// mint fact[mxn], inv[mxn];
// mint C(int n, int r){return fact[n] * inv[n-r] * inv[r];}
// mint snb(int n, int r){return C(n + r, n);}
vpii adj[mxn], cur; int n, k, ans = 0, sz[mxn], dep[mxn], mx[mxn]; bool vis[mxn]; vpii sub; 
struct segtree{
	int n; vi tree; 
	segtree(int x){
		n=x; tree.rs(2*n+5); 
	}
	void add(int k, int x){
		k+=n; tree[k]+=x; for(k/=2;k>=1;k/=2)tree[k]=tree[k*2]+tree[k*2+1];
	}
	void update(int k, int x){
		k+=n; tree[k]=x; for(k/=2;k>=1;k/=2)tree[k]=tree[k*2]+tree[k*2+1];
	}
	int quer(int l, int r){
		l+=n;r+=n; int ret = 0; while(l<=r){
			if(l%2)ret+=tree[l++]; if(r%2==0)ret+=tree[r--]; l/=2;r/=2;
		} return ret; 
	}
}; segtree S(mxn); 
void get_sz(int node, int from){sz[node]=1; for(auto [u,w]: adj[node])if(u!=from&&!vis[u])get_sz(u,node), sz[node]+=sz[u];}
int get_centroid(int node, int from, int tar){for(auto [u,w] : adj[node])if(u!=from&&!vis[u]&&sz[u]>tar)return get_centroid(u,node,tar); return node;}
void dfs(int node, int from){
	for(auto [u,w] : adj[node])if(u!=from&&!vis[u])dep[u]=dep[node]+1,mx[u]=max(mx[node],w),cur.eb(mx[u],u),dfs(u,node);
}
void solve(int node, int from){
	for(auto [u,w] : adj[node])if(u!=from&&!vis[u])sub.eb(mx[u],u),solve(u,node);
}
void centroid_decomp(int node){ 
	get_sz(node,-1); int c = get_centroid(node,-1,sz[node]/2); node=c;  vis[node]=1; cur.clear(); cur.eb(0,node); 
	mx[node]=dep[node]=0; dfs(node,-1); sort(all(cur)); int mxd = 0;
	for(auto [w,u] : cur){ //dep[u] + dep[v] <= w - k
		ckmax(mxd, dep[u]); if(w - k - dep[u] >= 0)ans += S.quer(0, w-k-dep[u]); 
		S.add(dep[u],1);
	} f0r(i,mxd+1)S.update(i, 0);
	for(auto [u,w] : adj[node])if(!vis[u]){
		sub.clear(); sub.eb(mx[u], u); solve(u,node); sort(all(sub)); mxd = 0;
		for(auto [w,u] : sub){ //dep[u] + dep[v] <= w - k 
			ckmax(mxd, dep[u]); if(w - k - dep[u] >= 0)ans -= S.quer(0, w-k-dep[u]); 
			S.add(dep[u],1);
		} 
		f0r(i,mxd+1)S.update(i, 0); 
	} //dout(ans);
	
	for(auto [u,w] : adj[node])if(!vis[u])centroid_decomp(u); 
}
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	//ifstream cin(".in");
	//ofstream cout(".out");
	// fact[0]=1;FOR(i,1,mxn)fact[i]=fact[i-1]*i;inv[mxn-1]=fact[mxn-1].inv();r0f(i,mxn-1)inv[i]=inv[i+1]*(i+1);
	cin>>n>>k; f0r(i,n-1){in3(a,b,c); a--;b--; adj[a].eb(b,c); adj[b].eb(a,c);} centroid_decomp(0); out(ans*2);
}

• Subtask 1: 15 / 15
• Subtask 2: 35 / 35
• Subtask 3: 60 / 60