Submission #397245

#	Time	Username	Problem	Language	Result	Execution time	Memory
397245		rocks03	Tropical Garden (IOI11_garden)	C++14	0 / 100	4 ms	5964 KiB

garden

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first
#define ss second
#define pb push_back
#define SZ(x) ((int)(x).size())
#define all(x) x.begin(), x.end()
#define debug(x) cout << #x << ": " << x << " "
#define nl cout << "\n"
#define rep(i, a, b) for(int i = (a); i < (b); i++)
#define per(i, a, b) for(int i = (a); i >= (b); i--)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int MAXK = 30;
const int MAXN = 2e5+100;
int N, M, P, nxt[2][MAXK][MAXN], wei[2][MAXK][MAXN];
vector<pii> g[MAXN];

void build(){
    rep(i, 0, N){
        sort(all(g[i]), greater<pii>());
        while(SZ(g[i]) > 2) g[i].pop_back();
        if(SZ(g[i]) < 2) g[i].pb(g[i][0]);
        nxt[0][0][i] = g[i][0].ss;
        wei[0][0][i] = g[i][0].ff;
        nxt[1][0][i] = g[i][1].ss;
        wei[1][0][i] = g[i][1].ff;
    }
    rep(k, 0, MAXK - 1){
        rep(i, 0, N){
            int u;
            u = nxt[0][k][i];
            nxt[0][k + 1][i] = nxt[0][k][u];
            wei[0][k + 1][i] = wei[0][k][u];
            if(wei[0][k][i] == wei[0][0][u]){
                nxt[0][k + 1][i] = nxt[1][k][u];
                wei[0][k + 1][i] = wei[1][k][u];
            }
            u = nxt[1][k][i];
            nxt[1][k + 1][i] = nxt[0][k][u];
            wei[1][k + 1][i] = wei[0][k][u];
            if(wei[1][k][i] == wei[0][0][u]){
                nxt[1][k + 1][i] = nxt[1][k][u];
                wei[1][k + 1][i] = wei[1][k][u];
            }
        }
    }
}

int jump(int v, int K){
    int w = -1;
    per(k, MAXK - 1, 0){
        if(K >> k & 1){
            if(wei[0][0][v] != w){
                w = wei[0][k][v];
                v = nxt[0][k][v];
            } else{
                w = wei[1][k][v];
                v = nxt[1][k][v];
            }
        }
    }
    return v;
}

int query(int K){
    int ans = 0;
    rep(i, 0, N){
        if(jump(i, K) == P)
            ans++;
    }
    return ans;
}

void answer(int x);

void count_routes(int N, int M, int P, int R[][2], int Q, int G[]){
    ::N = N, ::M = M, ::P = P;
  	per(m, M - 1, 0){
     	int u = R[m][0], v = R[m][1];
        g[u].pb({m, v});
        g[v].pb({m, u});
    }
    build();
    rep(q, 0, Q){
    	answer(query(G[q]));
    }
}

• Subtask 1: 0 / 49
• Subtask 2: 0 / 20
• Subtask 3: 0 / 31