Submission #1136377

#	Time	Username	Problem	Language	Result	Execution time	Memory
1136377		dombly	Tourism (JOI23_tourism)	C++20	10 / 100	5092 ms	25324 KiB

tourism

#include <bits/stdc++.h>

#define int long long 

#define pb push_back
 
#define F first
 
#define S second
 
using namespace std;
 
const int N = 1e5 + 10;

const int mod = 1e9 + 7;

const int inf = 1e9;

const int LOG = 20;

int in[N],out[N],up[N][LOG],timer = 0,a[N],c[N];
vector<int>g[N];

void Dfs(int x,int par) {
	in[x] = ++timer;
	up[x][0] = par;
	for(int j = 1; j < LOG; j++) up[x][j] = up[up[x][j - 1]][j - 1];
	for(int j : g[x]) {
		if(j != par) {
			Dfs(j,x);
		}
	}
	out[x] = timer;
}

void dfs(int x,int par) {
	for(int j : g[x]) {
		if(j != par) {
			dfs(j,x);
			a[x] += a[j];
		}
	}
}

bool In(int u,int v) {
	return in[u] <= in[v] && out[u] >= out[v];
}

int LCA(int u,int v) {
	if(In(u,v)) return u;
	if(In(v,u)) return v;
	for(int j = LOG - 1; j >= 0; j--) {
		if(up[u][j] > 0 && !In(up[u][j],v)) u = up[u][j];
	}
	return up[u][0];
}
 
signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

	int n,m,q;
	cin >> n >> m >> q;
	for(int i = 1; i < n; i++) {
		int u,v;
		cin >> u >> v;
		g[u].pb(v);
		g[v].pb(u);
	}
	Dfs(1,0);
	for(int i = 1; i <= m; i++) cin >> c[i];
	while(q--) {
		int l,r;
		cin >> l >> r;
		if(r - l == 0) {
			cout << 1 << "\n";
			continue;
		}
		for(int i = 1; i <= n; i++) a[i] = 0;
		for(int i = l; i < r; i++) {
			a[c[i]]++;
			a[c[i + 1]]++;
			a[up[LCA(c[i],c[i + 1])][0]] -= 2;
		}
		dfs(1,0);
		int ans = 0;
		for(int i = 1; i <= n; i++) if(a[i]) ans++;
		cout << ans << "\n";
	}
 	return 0;   
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 7
• Subtask 4: 0 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 41