Submission #1124415

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124415		Yang8on	Bitaro’s Party (JOI18_bitaro)	C++20	0 / 100	4 ms	4928 KiB

bitaro

#include <bits/stdc++.h>
#define Y8o "bitaro"
#define maxn (int) 1e5 + 5
#define ll long long
#define pii pair<int, int>
#define gb(i, j) ((i >> j) & 1)
#define all(x) x.begin(), x.end()
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define fi(i, a, b) for(int i = a; i <= b; i ++)
#define fid(i, a, b) for(int i = a; i >= b; i --)

//#define f first
//#define s second

using namespace std;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll GetRandom(ll l, ll r) {
    return uniform_int_distribution<ll> (l, r) (rng);
}
void iof() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL), cout.tie(NULL);
    if(fopen(Y8o".inp", "r"))
    {
        freopen(Y8o".inp", "r", stdin);
//        freopen(Y8o".out", "w", stdout);
    }
}
void ctime() {
    cerr << "\n" << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
}

const int inf = 1e9;
const int can = 100;

int n, m, Q;
int a[maxn], mx[maxn];
bool dd[maxn], dd2[maxn];
vector<int> o[maxn];
vector<pii> dp[maxn];

void cb(vector<pii>& A, vector<pii>& B, int v) {
    A.push_back({ 1, v });
    for(auto [x, rt] : B) A.push_back({ x + 1, rt });
    if(A.size() > can) {
        sort( all(A), greater<pii>() );
        while(A.size() > can) A.pop_back();
    }
}

void dfs(int u) {
    dd[u] = 1;
    for(int v : o[u]) {
        if(!dd[v]) dfs(v);
        cb(dp[u], dp[v], v);
    }
}

int calc(int u) {
    if(dd2[u]) return mx[u];
    for(int v : o[u]) {
        mx[u] = max(mx[u], calc(v) + 1);
    }
    return mx[u];
}

void solve() {
    cin >> n >> m >> Q;
    fi(i, 1, m) {
        int u, v; cin >> u >> v;
        o[v].push_back(u);
    }

    fi(i, 1, n) if(!dd[i]) {
        dfs(i);
    }
    fi(i, 1, n) dd[i] = 0, sort( all(dp[i]), greater<pii>() );

    fi(i, 1, Q) {
        int u, k; cin >> u >> k;
        fi(j, 1, k) cin >> a[j], dd[ a[j] ] = 1;

        if(k < can) {
            int ans = 0;
            for(auto [len, v] : dp[u]) {
                if(!dd[v]) { ans = len; break; }
            }
            cout << ( ans <= 0 ? -1 : ans ) << '\n';
        }
        else {
            fi(i, 1, n) {
                mx[i] = dd2[i] = 0;
                if(dd[i]) mx[i] = -inf;
            }
            int ans = calc(u);
            cout << ( ans <= 0 ? -1 : ans ) << '\n';
        }

        fi(j, 1, k) dd[ a[j] ] = 0;
    }
}

int main() {
    iof();

    int nTest = 1;
//    cin >> nTest;

    while(nTest --) {
        solve();
    }

    ctime();
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'void iof()':
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(Y8o".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86