Submission #447895

#	Time	Username	Problem	Language	Result	Execution time	Memory
447895		SirCovidThe19th	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	1494 ms	114708 KiB

bitaro

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

#define v vector
#define pii pair<int, int>
#define pb push_back
#define f first
#define s second

const int mx = 1e5+5, sq = 100;

int n, m, q; vector<int> adj[mx]; v<pii> far[mx]; bool use[mx];

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); 
    cin >> n >> m >> q;
    for (int i = 0; i < m; i++){ int a, b; cin >> a >> b; adj[a-1].pb(b-1); }
    auto merge = [&](v<pii> a, v<pii> b){ 
        v<pii> ret; v<int> vis; int x = 0, y = 0, szA = a.size(), szB = b.size();
        auto ins = [&](v<pii> &cur, int &i){ 
            if (!use[cur[i].f]) ret.pb(cur[i]);
            use[cur[i].f] = 1; vis.pb(cur[i].f); i++;
        };while (ret.size() <= sq and (x < szA or y < szB)){
            if (x < szA and (y >= szB or a[x].s+1 > b[y].s)) a[x].s++, ins(a, x);
            else ins(b, y);
        }for (auto i : vis){ use[i] = 0; } return ret;
    };for (int i = 0; i < n; i++) far[i].pb({i, 0});
    for (int i = 0; i < n; i++) for (int j : adj[i]) far[j] = merge(far[i], far[j]);
    while (q--){
        int t, y; cin >> t >> y; t--; int C[y], ans = -1; v<int> vis; 
        for (int &i : C) cin >> i, i--, use[i] = 1, vis.pb(i);
        if (y <= sq){ for (auto i : far[t]) if (!use[i.f]){ ans = i.s; break; } }
        else{
            int dp[t+1]; memset(dp, -1, sizeof(dp));
            for (int i = 0; i <= t; i++){
                if (!use[i]) dp[i] = max(dp[i], 0);
                for (int j : adj[i]) if (j <= t) dp[j] = max(dp[j], (dp[i] == -1) ? dp[i] : dp[i]+1);
            }ans = dp[t];
        }for (auto i : vis){ use[i] = 0; } cout<<ans<<endl;
    }
}
 

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