Submission #659543

#	Time	Username	Problem	Language	Result	Execution time	Memory
659543		Soul234	Tropical Garden (IOI11_garden)	C++14	100 / 100	2363 ms	28436 KiB

garden

#include "garden.h"
#include "gardenlib.h"

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

void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << h; if(sizeof...(t)) cerr << ", ";
    DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL

#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"
#define fi first
#define se second

using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
using db = long double;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;

void setIO(string NAME = "") {
    cin.tie(0)->sync_with_stdio(0);
    if(sz(NAME)) {
        freopen((NAME + ".inp").c_str(),"r",stdin);
        freopen((NAME + ".out").c_str(),"w",stdout);
    }
}

tcT> bool ckmin(T&a, const T&b) {
    return b < a ? a=b,1 : 0; }
tcT> bool ckmax(T&a, const T&b) {
    return b > a ? a=b,1 : 0; }

const int MOD = 1e9 + 7;
const ll INF = 1e18;

const int MX = 150005;

vi adj[MX<<1];

int fs[MX<<1], sc[MX<<1];

int nxt[MX<<1];

int dist[2][MX<<1];
int cycsz[2], cycDist[2][MX<<1];

bool vis[MX<<1];
int goal;

void dfs(int u, int id) {
    if(~dist[id][u]) return;
    if(~cycDist[id][u]) {
        dist[id][u] = cycDist[id][u];
        return;
    }
    if(u == goal) {
        dist[id][u] = 0;
        return;
    }
    dist[id][u] = MOD;
    if(dist[id][nxt[u]] == -1) dfs(nxt[u], id);
    ckmin(dist[id][u], dist[id][nxt[u]] + 1);
}

void count_routes(int N, int M, int P, int R[][2], int Q, int G[]) {
    memset(fs, -1, sizeof fs);
    memset(sc, -1, sizeof sc);

    R0F(i, M) {
        sc[R[i][0]] = fs[R[i][0]];
        fs[R[i][0]] = R[i][1];
        sc[R[i][1]] = fs[R[i][1]];
        fs[R[i][1]] = R[i][0];
    }

    F0R(i, N<<1) {
        if(i < N) {
            if(fs[fs[i]] == i) {
                nxt[i] = fs[i] + N;
            }
            else {
                nxt[i] = fs[i];
            }
        }
        else {
            if(sc[i-N] == -1) {
                nxt[i] = nxt[i-N];
            }
            else if(fs[sc[i-N]] == i-N) {
                nxt[i] = sc[i-N] + N;
            }
            else nxt[i] = sc[i-N];
        }
    }

    memset(cycDist, -1, sizeof cycDist);
    memset(dist, -1, sizeof dist);

    F0R(id, 2) {
        memset(vis, false, sizeof vis);
        int cur = P + id*N;
        while(cur >= 0 && !vis[cur]) {
            vis[cur] = 1;
            cycDist[id][cur] = cycsz[id]++;
            cur = nxt[cur];
        }

        F0R(i, N<<1) {
            if(~cycDist[id][i]) {
                cycDist[id][i] = (cycsz[id] - cycDist[id][i])%cycsz[id];
            }
        }

        goal = -1;

        if(cur != P + id*N) {
            cycsz[id] = 0;
            memset(cycDist[id], -1, sizeof cycDist[id]);
            goal = P + id*N;
        }

        F0R(i, N) if(dist[id][i] == -1) dfs(i, id);
    }


    F0R(i, Q) {
        int K = G[i];
        bool ok = false;
        int cnt = 0;
        F0R(u, N) {
            bool ok = false;
            F0R(id, 2) {
                ok |= (dist[id][u] == K || (cycsz[id] > 0 && K >= dist[id][u] && (K - dist[id][u])%cycsz[id] == 0));
            }
            cnt += ok;
        }
        answer(cnt);
    }
}

Compilation message (stderr)

garden.cpp: In function 'void count_routes(int, int, int, int (*)[2], int, int*)':
garden.cpp:148:14: warning: unused variable 'ok' [-Wunused-variable]
  148 |         bool ok = false;
      |              ^~
garden.cpp: In function 'void setIO(std::string)':
garden.cpp:43:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |         freopen((NAME + ".inp").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
garden.cpp:44:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |         freopen((NAME + ".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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