Submission #1150464

#	Time	Username	Problem	Language	Result	Execution time	Memory
1150464		mingga	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	1029 ms	410648 KiB

bitaro

#include "bits/stdc++.h"

using namespace std;

#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
// #define int long long
const int mod = 1e9 + 7;
const int inf = 2e9;
const int N = 1e5 + 7;
vector<int> g[N];
int n, m, q;
const int B = 330;

vector<pair<int, int>> path[N];
bool vis[N], del[N];
int dp[N];

signed main() {
    cin.tie(0) -> sync_with_stdio(0);
    #define task ""
    if(fopen(task ".INP", "r")) {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }
    cin >> n >> m >> q;
    for(int i = 1; i <= m; i++) {
        int u, v; cin >> u >> v;
        g[v].pb(u);
    }
    for(int u = 1; u <= n; u++) {
        for(int v : g[u]) {
            int i = 0, j = 0;
            vector<pair<int, int>> nxt;
            vector<int> sus;
            while(1) {
                if(i < sz(path[u]) and (j >= sz(path[v]) or path[u][i].se >= path[v][j].se + 1)) {
                    assert(i < sz(path[u]));
                    if(!vis[path[u][i].fi]) {
                        int x = path[u][i].fi, w = path[u][i].se;
                        nxt.pb({x, w});
                        vis[x] = 1;
                        sus.pb(x);
                    }
                    i++;
                } else if(j < sz(path[v]) and (i >= sz(path[u]) or path[v][j].se + 1 > path[u][i].se)) {
                    if(!vis[path[v][j].fi]) {
                        int x = path[v][j].fi, w = path[v][j].se;
                        nxt.pb({x, w + 1});
                        vis[x] = 1;
                        sus.pb(x);
                    }
                    j++;
                }
                if(i >= sz(path[u]) and j >= sz(path[v])) break;
                if(sz(nxt) >= B) break;
            }
            swap(path[u], nxt);
            for(int x : sus) vis[x] = 0;
        }
        if(sz(path[u]) < B and !vis[u]) path[u].pb({u, 0});
    }
    // for(int i = 1; i <= n; i++) {
    //     cout << "PATH " << i << ln;
    //     for(auto x : path[i]) {
    //         cout << x.fi << ' ' << x.se << ln;
    //     }
    // }
    for(int i = 1; i <= q; i++) {
        int t, y; cin >> t >> y;
        vector<int> sus;
        for(int j = 1; j <= y; j++) {
            int x; cin >> x;
            del[x] = 1;
            sus.pb(x);
        }
        if(y >= B) {
            memset(dp, -0x3f, sizeof dp);
            for(int i = 1; i <= t; i++) {
                if(!del[i]) dp[i] = 0;
                for(int v : g[i]) {
                    dp[i] = max(dp[i], dp[v] + 1);
                }
            }
            if(dp[t] < 0) dp[t] = -1;
            cout << dp[t] << ln;
        } else {
            int ans = -1;
            for(auto x : path[t]) {
                if(!del[x.fi]) {
                    ans = x.se;
                    break;
                }
            }
            cout << ans << ln;
        }
        for(int x : sus) del[x] = 0;
    }
    cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:27:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |         freopen(task ".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:28:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         freopen(task ".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 86 / 86