제출 #1017673

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1017673		ByeWorld	Mergers (JOI19_mergers)	C++14	100 / 100	1476 ms	194612 KiB

mergers

#include <bits/stdc++.h>
// #pragma GCC optimize("O3", "unroll-loops")
#define ll long long
#define int long long
#define pb push_back
#define fi first
#define se second
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
#define ld long double
using namespace std;
typedef pair<int,int> pii;
typedef pair<pii, int> ipii;
const int MAXN = 5e5+10;
const int MAXA = 9e3+20;
const ll INF = 1e9+10;
const int LOG = 13;
const int SQRT = 450;
const vector<int> NOL = {};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const vector<int> dx = {1, -1, 0, 0};
const vector<int> dy = {0, 0, 1, -1};
vector <int> key = {29, 31};
vector <int> mod = {998244353, 1000000007};
void chmx(int &a, int b){ a = max(a, b); }

int n, k;
vector <int> adj[MAXN], vec[MAXN];
int a[MAXN], tot[MAXN], u[MAXN], v[MAXN];
vector <int> tree[MAXN];

struct dsu {
	int par[MAXN], siz[MAXN];
	void bd(){
		for(int i=1; i<=n; i++){
			par[i] = i; siz[i] = 1;
		}
	}
	int f(int x){
		if(par[x]==x) return x;
		return par[x] = f(par[x]);
	}
	bool con(int x, int y){ return f(x) == f(y); }
	void mer(int x, int y){
		x = f(x); y = f(y);
		if(x==y) return;
		if(siz[x] > siz[y]) swap(x, y);
		par[x] = y; siz[y] += siz[x];
	}
} DSU;

int sub[MAXN], dep[MAXN], in[MAXN], tim, par[MAXN];
void dfs(int nw, int pa){
	dep[nw] = dep[pa]+1; par[nw] = pa; 
	sub[nw] = 1;
	for(auto nx : adj[nw]){
		if(nx==pa) continue;
		tree[nw].pb(nx);
		dfs(nx, nw);
		sub[nw] += sub[nx];
	}
}

int ANS[MAXN];
struct segtree {
	int st[4*MAXN], laz[4*MAXN];
	void bnc(int id, int l, int r){
		if(laz[id] == 0) return;
		st[lf] += (md-l+1); laz[lf] += laz[id];
		st[rg] += (r-md); laz[rg] += laz[id];
		laz[id] = 0;
	}
	int upd(int id, int l, int r, int x, int y){
		if(r<x || y<l) return st[id];
		if(x<=l && r<=y){ 
			laz[id]++; return st[id] += (r-l+1);
		}
		bnc(id, l, r);
		return st[id] = upd(lf, l, md, x, y) + upd(rg, md+1, r, x, y);
	}
	void out(int id, int l, int r){
		if(l==r){ ANS[l] = st[id]; return; }
		bnc(id, l, r);
		out(lf, l, md); out(rg, md+1, r);
	}
} ST;

int root[MAXN], arr[MAXN];
void bd(int nw, int roo){
	root[nw] = roo; in[nw] = ++tim; arr[tim] = nw;
	if(tree[nw].size() == 0) return;
	bd(tree[nw][0], roo);
	for(int j=1; j<tree[nw].size(); j++){
		bd(tree[nw][j], tree[nw][j]);
	}
}

void query(int x, int y){
	// cout << x << ' ' << y << " xyquery\n";
	// cout << root[x] << ' ' << root[y] <<" root xy\n";
	while(root[x] != root[y]){
		if(dep[root[x]] > dep[root[y]]) swap(x, y); // y bawah
		// root[y]+1 - y
		// root->nyimpen siapa root, in[root]+1 --> idxnya
		if(in[root[y]] <= in[y]){
			// cout << in[root[y]] << ' ' << in[y] << " in\n";
			ST.upd(1, 1, n, in[root[y]], in[y]);
		}
		y = par[root[y]];
	}
	if(dep[x] > dep[y]) swap(x, y); // y bawah
	if(in[x]+1 <= in[y]){
		// cout << in[x]+1 << ' ' << in[y] << " in\n";
		ST.upd(1, 1, n, in[x]+1, in[y]);
	}
	// cout << '\n';
}
vector <int> edge[MAXN];

bool cmp(int a, int b){
	return in[a] < in[b];
}
signed main(){
	// ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin >> n >> k; DSU.bd();
	for(int i=1; i<=n-1; i++){
		int x, y; cin >> x >> y; u[i] = x; v[i] = y;
		adj[x].pb(y); adj[y].pb(x);
	}
	for(int i=1; i<=n; i++){
		cin >> a[i]; tot[a[i]]++;
		vec[a[i]].pb(i);
	}
	// dfs hld
	dfs(1, 0);

	// build hld
	for(int i=1; i<=n; i++){
		if(tree[i].size() == 0) continue;
		for(int j=1; j<tree[i].size(); j++){
			if(sub[tree[i][0]] < sub[tree[i][j]])
				swap(tree[i][0], tree[i][j]);
		}
	}
	tim = 0; bd(1, 1);

	// per state 
	for(int i=1; i<=k; i++){
		if(vec[i].size() <= 1) continue;
		// cout << i << " done\n";
		sort(vec[i].begin(), vec[i].end(), cmp);
		for(int j=1; j<vec[i].size(); j++) query(vec[i][j-1], vec[i][j]);
		query(vec[i][0], vec[i].back());
	}
	// cout << " pp\n";
 	
 	// OUT segtree
 	ST.out(1, 1, n);
 	for(int i=1; i<=n; i++)
 		if(ANS[i]) DSU.mer(par[arr[i]], arr[i]);
 	// for(int i=1; i<=n; i++) cout << i << ' ' << ANS[i] << ' '<< arr[i] << " pp\n";
 	
 	// ANSwer
	for(int i=1; i<=n-1; i++){
		int x = DSU.f(u[i]), y = DSU.f(v[i]);
		if(x == y) continue;
		edge[x].pb(y); edge[y].pb(x);
	}
	int tot = 0;
	for(int i=1; i<=n; i++){
		if(edge[i].size() == 1) tot++;
	}
	cout << (tot+1)/2 << '\n';
}

컴파일 시 표준 에러 (stderr) 메시지

mergers.cpp: In function 'void bd(long long int, long long int)':
mergers.cpp:94:16: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   94 |  for(int j=1; j<tree[nw].size(); j++){
      |               ~^~~~~~~~~~~~~~~~
mergers.cpp: In function 'int main()':
mergers.cpp:141:17: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  141 |   for(int j=1; j<tree[i].size(); j++){
      |                ~^~~~~~~~~~~~~~~
mergers.cpp:153:17: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  153 |   for(int j=1; j<vec[i].size(); j++) query(vec[i][j-1], vec[i][j]);
      |                ~^~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 24 / 24
• Subtask 3: 14 / 14
• Subtask 4: 22 / 22
• Subtask 5: 30 / 30