Submission #91359

#	Time	Username	Problem	Language	Result	Execution time	Memory
91359		toloraia	Birthday gift (IZhO18_treearray)	C++14	56 / 100	4009 ms	47548 KiB

treearray

#include <bits/stdc++.h>
#define F first
#define S second
#define mp make_pair
#define pb push_back
#define ll long long
#define LEFT(a) ((a)<<1)
#define RIGHT(a) (LEFT(a) + 1)
#define MID(a,b) ((a+b)>>1)
#define MAX(a,b) ((a)>(b)?(a):(b))
#define MIN(a,b) ((a)<(b)?(a):(b))

using namespace std;
const int N = 4e5 + 5;

int n, m, Q;
vector < int > g[N];
int in[N], out[N];
int P[N][20];
int T;

void dfs (int k, int p){
    in[k] = ++T;
    P[k][0] = p;
    for (int i = 1; i < 20; i++)
        P[k][i] = P[P[k][i - 1]][i - 1];
    for (int i = 0; i < g[k].size(); i++)
        if (g[k][i] != p)
            dfs (g[k][i], k);
    out[k] = ++T;
}

int LCA (int u, int v){
    if (u == 0 || v == 0)return u + v;
    if (in[u] <= in[v] && out[v] <= out[u])
        return u;
    if (in[v] <= in[u] && out[u] <= out[v])
        return v;
    int I = u;
    for (int i = 19; i >= 0; i--){
        if (P[I][i] == 0)
            continue;
        if (in[P[I][i]] <= in[v] && out[v] <= out[P[I][i]])
            continue;
        I = P[I][i];
    }
    return P[I][0];
}

int a[N], S;
int le[N], ri[N];

int main()
{
    ios::sync_with_stdio(false);
    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>>a[i];
    S = sqrt(m - 1) + 1;
    for (int i = 0; i < S * S; i += S){
        le[i + 1] = a[i + 1];
        for (int j = i + 2; j <= i + S; j++)
            le[j] = LCA (a[j], le[j - 1]);
        ri[i + S] = a[i + S];
        for (int j = i + S - 1; j >= i + 1; j--)
            ri[j] = LCA (a[j], ri[j + 1]);
    }
    while (Q--){
        int t;
        cin>>t;
        if (t == 1){
            int ind, x;
            cin>>ind>>x;
            a[ind] = x;
            int i = (ind - 1) / S * S;
            le[i + 1] = a[i + 1];
            for (int j = i + 2; j <= i + S; j++)
                le[j] = LCA (a[j], le[j - 1]);
            ri[i + S] = a[i + S];
            for (int j = i + S - 1; j >= i + 1; j--)
                ri[j] = LCA (a[j], ri[j + 1]);
            continue;
        }
        int l, r, v;
        cin>>l>>r>>v;
        int p1 = -1, p2 = -1;
        for (int L = 1; L <= S * S && p1 == -1; L += S){
            if (r < L - 1 || L < l)
                continue;
            int R = L - 1;
            int X = 0;
            while (R + S <= r && in[v] <= in[le[R + S]] && out[le[R + S]] <= out[v]){
                R += S;
                X = LCA (X, le[R]);
            }
            int x = L, y = R, xx, yy;
            for (int i = 10; i >= 0; i--){
                xx = x - (1<<i);
                if (xx >= L - S && xx >= l && in[v] <= in[ri[xx]] && out[ri[xx]] <= out[v])
                    x = xx;
            }
            for (int i = 10; i >= 0; i--){
                yy = y + (1<<i);
                if (yy <= R + S && yy <= r && in[v] <= in[le[yy]] && out[le[yy]] <= out[v])
                    y = yy;
            }
            if (x < L)
                X = LCA (X, ri[x]);
            if (R < y)
                X = LCA (X, le[y]);
            if (X == v && l <= x && y <= r){
                p1 = x;
                p2 = y;
            }
            //cout<<x<<" "<<y<<"   "<<X<<" "<<S<<" "<<L<<" "<<R<<" "<<le[R + S]<<endl;
            L = max (L, R + 1 - S);
        }
        if (p1 != -1){
            cout<<p1<<" "<<p2<<endl;
            continue;
        }
        for (int i = 0; i < S * S && p1 == -1; i += S){
            for (int L = max (i + 1, l); L <= i + S && L <= r && p1 == -1; L++){
                int R = L - 1;
                int X = 0;
                while (R < r && in[v] <= in[a[R + 1]] && out[a[R + 1]] <= out[v]){
                    R++;
                    X = LCA (X, a[R]);
                }
                if (X == v){
                    p1 = L;
                    p2 = R;
                }
                L = max (L, R);
            }
        }
        cout<<p1<<" "<<p2<<endl;
    }
    return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'void dfs(int, int)':
treearray.cpp:27:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < g[k].size(); i++)
                     ~~^~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 0 / 44