Submission #1158152

#	Time	Username	Problem	Language	Result	Execution time	Memory
1158152		akzytr	Bitaro’s Party (JOI18_bitaro)	C++20	7 / 100	2099 ms	129148 KiB

bitaro

#include <bits/stdc++.h>
#define ve vector
#define ar array 
#define pb push_back
#define ins insert

#define endl '\n'
#define ll long long
using namespace std;

const int MXN = 1e5+1;
ve<int> adj[MXN];
int blck[MXN];
int from[MXN];

ve<pair<int, int>> madst[MXN+1];
const int BLCK = 100;

ll ansgy(ll x, ll i){
    priority_queue<pair<int, int>> g;
    int dst[MXN];
    fill(dst, dst+MXN, -1);
    g.push({0, x});
    while(!g.empty()){
        auto top = g.top();
        g.pop();
        if(top.first > dst[top.second]){
            dst[top.second] = top.first;
            for(int i : adj[top.second]){
                g.push({1+top.first, i});
            }
        }
    }
    int as = -1;
    for(int j = 0; j < MXN; j++){
        if(blck[j] != i){
            as = max(as, dst[j]);
        }
    }

    return as;
}

void populate(ll x){
    madst[x].pb({0, x});
    ve<int> co;
    for(int i : adj[x]){
        for(auto [dst, y] : madst[i]){
            if(from[y] == -1){
                co.pb(y);
                from[y] = dst+1;
            }
            else{
                from[y] = max(from[y], dst+1);
            }
        }
    }
    for(int i : co){
        madst[x].pb({from[i], i});
    }
    sort(madst[x].rbegin(), madst[x].rend());
    while(madst[x].size() > BLCK){
        madst[x].pop_back();
    }
    for(int i : co){
        from[i] = -1;
    }
}

int main(){
    fill(blck, blck+MXN, -1);
    fill(from, from+MXN, -1);

    int n, m, q;
    scanf("%d %d %d", &n, &m, &q);

    for(int i = 0; i < m; i++){
        int a, b;
        scanf("%d %d", &a, &b);
        adj[b].pb(a);
    }
    for(int i = 1; i <= n; i++){
        populate(i);
    }
    for(int i = 0; i < q; i++){
        int t, sz;
        scanf("%d %d", &t, &sz);
        int ans = -1;
        for(int j = 0; j < sz; j++){
            int y;
            scanf("%d", &y);
            blck[y] = i;
        }
        if(sz >= BLCK){
            ans = ansgy(t, i);
        }
        else{
            for(auto [u,v]: madst[t]){
                if(blck[v] != i){
                    ans = u;
                    break;
                }
            }
        }
        printf("%d\n",ans);
    }
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:75:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |     scanf("%d %d %d", &n, &m, &q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:79:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |         scanf("%d %d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~~
bitaro.cpp:87:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |         scanf("%d %d", &t, &sz);
      |         ~~~~~^~~~~~~~~~~~~~~~~~
bitaro.cpp:91:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |             scanf("%d", &y);
      |             ~~~~~^~~~~~~~~~

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