Cod sursa(job #1382420)

Utilizator Eugen01Vasilescu Eugen Eugen01 Data 8 martie 2015 23:21:09
Problema Heavy Path Decomposition Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 5.13 kb
#include<iostream>
#include<fstream>
#include<vector>
#include<algorithm>

#define Nmax 200005
#define LogMax 20

using namespace std;

ifstream in("disconnect.in");
ofstream out("disconnect.out");

int chainNumber;
int val[Nmax], level[Nmax], children[Nmax], AI[4 * Nmax];
int chainSize[Nmax], chain[Nmax], chainParent[Nmax], chainLevel[Nmax], chainOffset[Nmax];
bool visited[Nmax];
vector<int> G[Nmax], chains[Nmax];
int D[Nmax][LogMax];

void DFS(int node, int L, int T)
{
    bool isLeaf = true;
    int biggestChain = -1, maxChildren = 0;

    visited[node] = true;
    level[node] = L;
    children[node] = 1;

    D[node][0] = T;
    for (int i = 1; i < LogMax; i++)
    {
        if (D[node][i - 1] == -1)
            D[node][i] = -1;
        else
            D[node][i] = D[D[node][i - 1]][i - 1];
    }

    for (int i = 0; i < G[node].size(); i++)
    {
        int nextNode = G[node][i];

        if (visited[nextNode]) continue;
        isLeaf = false;

        DFS(nextNode, L + 1, node);

        children[node] += children[nextNode];

        if (biggestChain == -1)
        {
            biggestChain = chain[nextNode];
            maxChildren = children[nextNode];
        }
        else if (children[nextNode] > maxChildren)
        {
            biggestChain = chain[nextNode];
            maxChildren = children[nextNode];
        }
    }

    if (isLeaf)
    {
        chainNumber++;
        chainSize[chainNumber] = 1;
        chain[node] = chainNumber;

        chains[chainNumber].push_back(node);
        return;
    }

    chainSize[biggestChain]++;
    chains[biggestChain].push_back(node);
    chain[node] = biggestChain;

    for (int i = 0; i < G[node].size(); i++)
    {
        int nextNode = G[node][i];

        if (chain[node] == chain[nextNode] || level[nextNode] < level[node]) continue;

        chainParent[chain[nextNode]] = node;
        chainLevel[chain[nextNode]] = level[node];
    }
}

void update(int node, int left, int right, int position, int offset, int value)
{
    int middle = (left + right) / 2;

    if (left == right)
    {
        AI[node + offset] = value;
        return;
    }

    if (middle >= position) update(node * 2, left, middle, position, offset, value);
    if (middle < position) update(node * 2 + 1, middle + 1, right, position, offset, value);

    AI[node + offset] = AI[node * 2 + offset] + AI[node * 2 + 1 + offset];
}

int query(int node, int left, int right, int a, int b, int offset)
{
    int middle = (left + right) / 2;
    int result = 0;

    if (a <= left && b >= right)
    {
        return AI[node + offset];
    }

    if (middle >= a) result = query(node * 2, left, middle, a, b, offset);
    if (middle < b) result += query(node * 2 + 1, middle + 1, right, a, b, offset);

    return result;
}


int goUp(int x, int nr)
{
    for (int i = LogMax - 1; i >= 0; i--)
        if ((1 << i) <= nr)
        {
            x = D[x][i];
            nr -= (1 << i);
        }

    return x;
}

int LCA(int x, int y)
{
    if (level[x] < level[y]) swap(x, y);
    x = goUp(x, level[x] - level[y]);

    if (x == y) return x;

    for (int i = LogMax - 1; i >= 0; i--)
        if (D[x][i] != -1 && D[x][i] != D[y][i])
        {
            x = D[x][i];
            y = D[y][i];
        }
    return D[x][0];
}

int main()
{
    int n, t;
    in >> n >> t;

    for (int i = 1; i < n; i++)
    {
        int x, y;
        in >> x >> y;

        G[x].push_back(y);
        G[y].push_back(x);
    }

    DFS(1, 1, -1);
    for (int i = 1; i <= chainNumber; i++)
        reverse(chains[i].begin(), chains[i].end());

    chainOffset[1] = 0;
    for (int i = 1; i <= chainNumber; i++)
        chainOffset[i + 1] = chainOffset[i] + 4 * chainSize[i];

    int V = 0, x, y;
    while (t--)
    {
        int type, a, b;
        in >> type >> a >> b;

        x = a ^ V;
        y = b ^ V;

        a = x;
        b = y;

        if (type == 1)
        {
            if (level[x] > level[y])
                swap(x, y);

            val[y] = 1;
            update(1, 1, chainSize[chain[y]], level[y] - chainLevel[chain[y]], chainOffset[chain[y]], 1);
        }
        else
        {
            int result = 0;

            while (1)
            {
                if (chain[x] == chain[y])
                {
                    if (level[x] > level[y])
                        swap(x, y);

                    int value = query(1, 1, chainSize[chain[x]], level[x] - chainLevel[chain[x]], level[y] - chainLevel[chain[x]], chainOffset[chain[x]]);
                    result += value;

                    break;
                }
                else
                {
                    if (chainLevel[chain[x]] < chainLevel[chain[y]])
                        swap(x, y);

                    int value = query(1, 1, chainSize[chain[x]], 1, level[x] - chainLevel[chain[x]], chainOffset[chain[x]]);
                    result += value;

                    x = chainParent[chain[x]];
                }
            }

            result -= val[LCA(a, b)];

            if (result <= 0)
            {
                out << "YES\n";
                V = a;
            }
            else
            {
                out << "NO\n";
                V = b;
            }
        }
    }
}