Submission #639742

#	Time	Username	Problem	Language	Result	Execution time	Memory
639742		Hacv16	Tropical Garden (IOI11_garden)	C++17	49 / 100	88 ms	38668 KiB

garden

#include<bits/stdc++.h>
#include "garden.h"
#include "gardenlib.h"
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int MAX = 2e5 + 15;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;

#define pb push_back
#define sz(x) (int) x.size()
#define fr first
#define sc second
#define mp make_pair
#define all(x) x.begin(), x.end()
#define dbg(x) cerr << #x << ": " << "[ " << x << " ]\n"

void count_routes(int n, int m, int p, int r[][2], int q, int qrs[]) {
    vector<vector<int>> adj(n), rev(2 * n);
    vector<int> pai(2 * n, -1);

    for(int i = 0; i < m; i++){
        int u = r[i][0], v = r[i][1];
        if(sz(adj[u]) < 2) adj[u].pb(v);
        if(sz(adj[v]) < 2) adj[v].pb(u);
    }

    for(int i = 0; i < n; i++){
        for(int j = 0; j < min(2, sz(adj[i])); j++){
            int v = adj[i][j];
            int cur = (adj[v][0] == i) * n + v;
            pai[j * n + i] = cur;
        }
    }

    for(int i = n; i < 2 * n; i++)
        if(pai[i] == -1) pai[i] = pai[i - n];

    for(int i = 0; i < 2 * n; i++)
        rev[pai[i]].pb(i); 
    
    vector<bool> seen(2 * n);

    function<void(int, int , int&, vector<int>&)> 
    dfs = [&](int u, int end, int &len, vector<int> &dist){
        seen[u] = true;

        for(auto v : rev[u]){
            if(v == end){
                len = dist[u] + 1;
                return;
            }

            if(seen[v]) continue;

            dist[v] = dist[u] + 1;
            dfs(v, end, len, dist);
        }
    };

    vector<int> cyc(2, INF);
    vector<vector<int>> dist(2, vector<int>(2 * n, -1));

    dist[0][p] = dist[1][p + n] = 0;
    dfs(p, p, cyc[0], dist[0]);
    fill(all(seen), false);
    dfs(p + n, p + n, cyc[1], dist[1]);

    vector<vector<int>> fdist(2, vector<int>(2 * MAX));

    for(int i = 0; i < 2; i++){
        for(int j = 0; j < n; j++){
            if(dist[i][j] == -1) continue;
            fdist[i][dist[i][j]]++;
        }
    }

    for(int i = 0; i < q; i++){
        int k = qrs[i], ans = 0;
        
        for(int j = 0; j < 2; j++){
            for(int d = k % cyc[j]; d <= min(n, k); d += cyc[j])
                ans += fdist[j][d];
        }

        answer(ans);
    }
}

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