Submission #518649

#	Time	Username	Problem	Language	Result	Execution time	Memory
518649		ac2hu	Untitled (POI11_ins)	C++14	0 / 100	979 ms	131076 KiB

Main

#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 10;
vector<int> adj[N];
int n;
int mx[N], nodes[N], total_subtree[N], full_total[N], ans[N];
struct LCA{
    int n,l,timer;
    vector<int> tin, tout,dist;
    vector<vector<int>> up;
    LCA(int root,int siz){
		n = siz; timer = 0; l = ceil(log2(n));
        tin.resize(n); tout.resize(n); dist.resize(n,0); up.assign(n,vector<int>(l + 1));
        dfs0(root,root);
    }
    void dfs0(int v, int p){
        tin[v] = ++timer;
        up[v][0] = p;
        for (int i = 1; i <= l; ++i){
            up[v][i] = up[up[v][i-1]][i-1];
        }
        for (int u : adj[v]) {
            if (u != p){
            	dist[u] = dist[v] + 1;
                dfs0(u, v);
            }
        }
        tout[v] = ++timer;
    }
    // Check if u is ancestor of v
    bool is_ancestor(int u,int v){
        return tin[u] <= tin[v] && tout[u] >= tout[v];
    }
    // Find LCA of u and v
    int lcaquery(int u,int v){
        if (is_ancestor(u, v))
            return u;
        if (is_ancestor(v, u))
            return v;
        for (int i = l; i >= 0; --i) {
            if (!is_ancestor(up[u][i], v))
                u = up[u][i];
        }
        return up[u][0];
    }
    int distance(int u,int v){
    	int ll = lcaquery(u,v);
    	return dist[u] + dist[v] - 2*dist[ll];
    }
};
void dfs(int i,int p){
	for(auto e : adj[i]){
		if(e == p)continue;
		mx[e] = mx[i] + 1;
		dfs(e,i);
	}
}
void dfs1(int i,int p){
	nodes[i] = 1;
	total_subtree[i] = 0;
	for(int e : adj[i]){
		if(e == p)continue;
		dfs1(e,i);
		nodes[i] += nodes[e];
		total_subtree[i] += total_subtree[e] + nodes[e];
	}
}
void dfs2(int i,int p){
	int mx = n - 1 - nodes[i];
	for(int e : adj[i]){
		if(e == p)continue;
		full_total[e] = full_total[i] - nodes[e] + n - nodes[e];
		dfs2(e,i);
		mx = max(mx, nodes[e]);
	}
	if(mx > n - mx)
		ans[i] = -1;
}
signed main() {
	iostream::sync_with_stdio(false);
	cin.tie(nullptr);cout.tie(nullptr);
	cin >> n;
	for(int i = 0;i<n - 1;i++){
		int a,b;cin >> a >> b;
		a--;b--;
		adj[a].push_back(b);
		adj[b].push_back(a);
	}
	LCA lc(0,n + 1);
	pair<int,int> dia;
	dia.first = max_element(lc.dist.begin(),lc.dist.end()) - lc.dist.begin();
	dfs(dia.first,-1);
	dia.second = max_element(mx, mx + n) - mx;
	for(int i =0;i<n;i++){
		mx[i] = max(lc.distance(i,dia.first), lc.distance(i,dia.second));
	}
	dfs1(0,-1);
	full_total[0] = total_subtree[0];
	dfs2(0,-1);
	// for(int i = 0;i<n;i++)
	// 	cout << full_total[i] << " ";
	// cout << "\n";
	for(int i = 0;i<n;i++){
		if(ans[i] != -1){
			ans[i] = 2*full_total[i] - mx[i];
		}
	}
	for(int i = 0;i<n;i++)
		cout << ans[i] << "\n";
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10