Submission #418589

#	Time	Username	Problem	Language	Result	Execution time	Memory
418589		cpp219	Bitaro’s Party (JOI18_bitaro)	C++14	7 / 100	399 ms	448992 KiB

bitaro

#pragma GCC optimization "O2"
#pragma GCC optimization "unroll-loop"
#pragma GCC target ("avx2")

#include <bits/stdc++.h>
#define ll int
#define ld long double
#define fs first
#define sc second
using namespace std;
const ll N = 3e5 + 9;
const ll inf = 1e9 + 7;
typedef pair<ll,ll> LL;
vector<ll> g[N],rg[N],v;
ll n,m,Q,x,y,sz,target,S,val[N];
ll ban[N];
ll DFS(ll u){
    if (val[u] != -1) return val[u];
    if (u == target) return 0;
    ll ans = -2*inf;
    for (auto i : g[u]) ans = max(ans,1 + DFS(i));
    return val[u] = ans;
}

deque<LL> dq[N]; /// fs = val    sc = id

void Merge(deque<LL> &a,deque<LL> b){
    deque<LL> res; //cout<<a.size(); exit(0);
    while(res.size() < S){
        LL c1 = {-inf,0},c2 = {-inf,0};
        if (!a.empty()) c1 = a.front();
        if (!b.empty()) c2 = b.front();
        c2.fs++; res.push_back(max(c1,c2));
        if (max(c1,c2) == a.front()){
            a.pop_front();
            if (c1 == c2) b.pop_front();
        }
        else{
            b.pop_front();
            if (c1 == c2) a.pop_front();
        }
    }
    a.clear();
    for (auto i : res) a.push_back(i);
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    #define task "tst"
    if (fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        //freopen(task".out", "w", stdout);
    }
    cin>>n>>m>>Q; S = sqrt(n);
    while(m--){
        cin>>x>>y;
        g[x].push_back(y); rg[y].push_back(x);
    }
    for (ll i = 1;i <= n;i++){
        deque<LL> now; now.push_back({-1,i});
        Merge(dq[i],now);
        for (auto j : rg[i]) Merge(dq[i],dq[j]);
    }
    /*
    for (ll i = 1;i <= n;i++){
        cout<<i<<":\n";
        for (auto j : dq[i]) cout<<j.fs<<" "<<j.sc<<"\n"; cout<<"\n";
    }
    return 0;*/
    while(Q--){
        cin>>target>>sz; v.clear();
        for (ll i = 1;i <= sz;i++) cin>>x,v.push_back(x),ban[x] = 1;
        if (sz >= S){
            memset(val,-1,sizeof(val));
            ll ans = -1;
            for (ll i = 1;i <= n;i++){
                if (ban[i]) continue;
                ans = max(ans,DFS(i)); //cout<<i<<" "<<DFS(i)<<"\n";
            }
            cout<<ans<<"\n";
        }
        else{
            LL ans = {-1,0};
            for (auto i : dq[target]) if (!ban[i.sc]) ans = max(ans,i);
            cout<<ans.fs<<"\n";
        }
        for (auto i : v) ban[i] = 0;
    }
}

Compilation message (stderr)

bitaro.cpp:1: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    1 | #pragma GCC optimization "O2"
      | 
bitaro.cpp:2: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    2 | #pragma GCC optimization "unroll-loop"
      | 
bitaro.cpp: In function 'void Merge(std::deque<std::pair<int, int> >&, std::deque<std::pair<int, int> >)':
bitaro.cpp:29:22: warning: comparison of integer expressions of different signedness: 'std::deque<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   29 |     while(res.size() < S){
      |           ~~~~~~~~~~~^~~
bitaro.cpp: In function 'int main()':
bitaro.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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