Submission #487884

#	Time	Username	Problem	Language	Result	Execution time	Memory
487884		ljuba	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	1221 ms	214208 KiB

bitaro

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef long double ld;
 
typedef vector<int> vi;
typedef vector<ll> vll;
 
typedef vector<vi> vvi;
typedef vector<vll> vvll;
 
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 
typedef vector<pii> vpii;
typedef vector<pll> vpll;
 
typedef vector<vpii> vvpii;
typedef vector<vpll> vvpll;
 
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)(x).size()
#define fi first
#define se second
 
template<class T> bool ckmin(T &a, const T &b) {return a > b ? a = b, 1 : 0;}
template<class T> bool ckmax(T &a, const T &b) {return a < b ? a = b, 1 : 0;}
 
namespace debug {
    void __print(int x) {cerr << x;}
    void __print(long long x) {cerr << x;}
    void __print(double x) {cerr << x;}
    void __print(long double x) {cerr << x;}
    void __print(char x) {cerr << '\'' << x << '\'';}
    void __print(const string &x) {cerr << '\"' << x << '\"';}
    void __print(const char *x) {cerr << '\"' << x << '\"';}
    void __print(bool x) {cerr << (x ? "true" : "false");}
 
    template<typename T, typename V>
    void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
    template<typename T>
    void __print(const T &x) {int f = 0; cerr << '{'; for(auto z : x) cerr << (f++ ? "," : ""), __print(z); cerr << "}";}
    void _print() {cerr << "]\n";}
    template <typename T, typename... V>
    void _print(T t, V... v) {__print(t); if(sizeof...(v)) cerr << ", "; _print(v...);}
 
#ifdef ljuba
#define dbg(x...) cerr << "\e[91m" << "LINE(" << __LINE__ << ") -> " << "[" << #x << "] = ["; _print(x)
#else
#define dbg(x...)
#endif
}
 
using namespace debug;
 
const char nl = '\n';
 
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
 
/*
погледај сампле тестове, пре него што имплементираш (можда имаш погрешну идеју) 
уместо да разматраш неке глупе случајеве на папиру, размишљај заправо о задатку
*/

const int mxN = 1e5 + 12;

const int K = 250;

const int INF = 1e9 + 12;

vi adj2[mxN];

int kosta[mxN];
vpii moze[mxN];

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

    for(int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        --u, --v;
        adj2[v].pb(u);
    }

    {
        //William Lin's idea
        vi prosli(n);
        for(int i = 0; i < n; ++i) {
            vi moguci{i};

            for(auto e : adj2[i]) {
                for(auto z : moze[e]) {
                    if(!prosli[z.se]) {
                        moguci.pb(z.se);
                    }
                    ckmax(prosli[z.se], z.fi + 1);
                }
            }

            nth_element(moguci.begin(), moguci.begin()+min(K, sz(moguci)), moguci.end(), [&](int a, int b) {
                return prosli[a] > prosli[b];
            });

            for(int j = 0; j < min(K, sz(moguci)); ++j) {
                int x = moguci[j];
                moze[i].pb({prosli[x], x});
            }
            for(auto z : moguci) prosli[z] = 0;
        }
    }

    for(int i = 0; i < n; ++i) {
        dbg(i, moze[i]);
    }


    vector<bool> marked(n);

    for(int iter = 0; iter < q; ++iter) {
        int s;
        cin >> s;
        --s;
        int ima;
        cin >> ima;
        vi bruh(ima);
        for(auto &z : bruh) cin >> z, --z;

        for(auto z : bruh) {
            marked[z] = true;
        }

        int odg = -1;

        if(ima <= K) {
            for(auto z : moze[s]) {
                if(!marked[z.se]) {
                    ckmax(odg, z.fi);
                }
            }
        } else {
            //dp
            vi dp(n, -INF);
            for(int i = 0; i < n; ++i) {
                if(marked[i]) dp[i] = -INF;
                else dp[i] = 0;
                for(auto e : adj2[i]) {
                    ckmax(dp[i], dp[e] + 1);
                }
            }
            odg = dp[s];
            if(odg < 0) odg = -1;
        }

        cout << odg << nl;

        for(auto z : bruh) {
            marked[z] = false;
        }
    }
}
 
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 
    int testCases = 1;
    //cin >> testCases;
    while(testCases--)
        solve();
}

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