Submission #1280178

#	Time	Username	Problem	Language	Result	Execution time	Memory
1280178		MinhKien	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	773 ms	410820 KiB

bitaro

#include <iostream>
#include <vector>

#define MASK(i) (1 << (i))
#define pub push_back
#define all(v) v.begin(), v.end()
#define compact(v) v.erase(unique(all(v)), end(v))
#define ii pair < int, int >
#define fi first
#define se second
#define endl "\n"
#define sz(v) (int)(v).size()
#define dbg(x) "[" #x " = " << (x) << "]"
#define vi vector<int>

using namespace std;

template<class T> bool minimize(T& a, T b){if(a > b) return a = b, true;return false;}
template<class T> bool maximize(T& a, T b){if(a < b) return a = b, true;return false;}

typedef long long ll;
typedef long double ld;

const int MAX = 1e5 + 15;
const int block_sz = 350;

int n, m, q;
vector<int> g[MAX];
vector<ii> dp[MAX];
bool busy[MAX];
int f[MAX];
bool opt[MAX];

vector <ii> combine(vector <ii> &a, vector <ii> &b) {
    vector<ii> c;
    int i = 0, j = 0;
    while(i < sz(a) || j < sz(b)){
        if(sz(c) == block_sz) break;
        if(i == sz(a)){
            if(!opt[b[j].se]){
                opt[b[j].se] = true;
                c.push_back(b[j]);
                c.back().fi++;
            }
            j++;
            continue;
        }
        if(j == sz(b)){
            if(!opt[a[i].se]){
                opt[a[i].se] = true;
                c.push_back(a[i]);
            }
            i++;
            continue;
        }

        if(a[i].fi > b[j].fi){
            if(!opt[a[i].se]){
                opt[a[i].se] = true;
                c.push_back(a[i]);
            }
            i++;
        }
        else{
            if(!opt[b[j].se]){
                opt[b[j].se] = true;
                c.push_back(b[j]);
                c.back().fi++;
            }
            j++;
        }
    }
    for(auto e : c) opt[e.se] = false;
    return c;
}

void solve(){
    cin >> n >> m >> q;

    for(int i = 1; i <= m; i++){
        int u, v; cin >> u >> v;
        g[v].push_back(u); //reverse edge
    }

    for(int u = 1; u <= n; u++){
        for(int v : g[u]){
            dp[u] = combine(dp[u], dp[v]);
        }
        dp[u].push_back(ii(0, u));
    }

    while(q--){
        int u, num; cin >> u >> num;
        vector<int> ban;
        while(num--){
            int x; cin >> x;
            ban.push_back(x);
            busy[x] = true;
        }

        if(sz(ban) < block_sz){
            bool ok = false;
            for(auto &[k, node] : dp[u]){
                if(!busy[node]){
                    ok = true;
                    cout << k << endl;
                    break;
                }
            }
            if(!ok) cout << -1 << endl;
        }
        else{
            fill(f + 1, f + 1 + n, 0);
            int ans = 0;
            f[u]++;//push idx +1
            for(int i = u; i >= 1; i--){
                if(!f[i]) continue;
                if(!busy[i]) maximize(ans, f[i]);
                for(int j : g[i]) maximize(f[j], f[i] + 1);
            }
            ans--;
            cout << ans << endl;
        }

        for(int x : ban) busy[x] = false;
    }
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    #define task "task"

    if(fopen(task".INP", "r")){
        freopen(task".INP", "r", stdin);
        freopen(task".OUT", "w", stdout);
    }

    int t; t = 1; //cin >> t;
    while(t--) solve();
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:136:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  136 |         freopen(task".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:137:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  137 |         freopen(task".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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