Submission #994503

#	Time	Username	Problem	Language	Result	Execution time	Memory
994503		yeediot	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	945 ms	122704 KiB

bitaro

#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmax(x,y) x= x>y?x:y
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float 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 char *x) {cerr << '\"' << x << '\"';}
void __print(const string &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 &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
#ifdef local
void CHECK();
void setio(){
    freopen("/Users/iantsai/cpp/input.txt","r",stdin);
    freopen("/Users/iantsai/cpp/output.txt","w",stdout);
}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
#define TOI_is_so_de ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);setio();
const int mxn = 2e5+5;
vector<int> radj[mxn];
vector<pair<int, int>> lp[mxn];
bool ex[mxn];
pair<int, int>mx[mxn];
int siz, t, k, dis[mxn], tmp[mxn];
int bfs(int st){
    fill(dis+1, dis+1+st, 0);
    for(int i=1;i<=st;i++){
        for(auto u : radj[i]){
            chmax(dis[i], dis[u]+1);
        }
        if(dis[i] == 0 and ex[i]){
            dis[i] = -1;
        }
    }
    return dis[st];
}
signed main(){
    TOI_is_so_de;
    int n, m, q;
    cin >> n >> m >> q;
    siz = sqrt(q*n/(m+1));
    debug(siz);
    for(int i = 0; i < m; i++){
        int v, u;
        cin >> v >> u;
        radj[u].pb(v);
    }
    for(int v = 1; v <= n; v++){
        vector<int> e;
        lp[v].pb({0, v});
        for(auto u : radj[v]){
            for(auto [l, k] : lp[u]){
                if(mx[k].S != v){
                    mx[k].F = l+1;
                    mx[k].S = v;
                    e.pb(k);
                }
                else{
                    chmax(mx[k].F, l+1);
                }
            }
        }
        for(auto u : e){
            lp[v].pb({mx[u].F, u});
        }
        sort(all(lp[v]),greater<pii>());
        while(sz(lp[v]) > siz){
            lp[v].pop_back();
        }
    }
    while(q--){
        cin >> t >> k;
        for(int i=0;i<k;i++){
            cin >> tmp[i];
            ex[tmp[i]] = 1;
        }
        if(k >= siz){
            cout << bfs(t) << '\n';
        }
        else{
            int ans = -1;
            for(auto [l, u] : lp[t]){
                if(ex[u]) continue;
                chmax(ans, l);
            }
            cout << ans << '\n';
        }
        for(int i=0;i<k;i++){
            ex[tmp[i]] = 0;
        }
    }
    #ifdef local
    CHECK();
    #endif
}
/*
input:
 mx^2 = qn
*/
#ifdef local
void CHECK(){
    cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
     function<bool(string,string)> compareFiles = [](string p1, string p2)->bool {
         std::ifstream file1(p1);
         std::ifstream file2(p2);
         if (!file1.is_open() || !file2.is_open())return false;
         std::string line1, line2;
         while (getline(file1, line1) && getline(file2, line2)) {
             if (line1 != line2)return false;
         }
         int cnta=0,cntb=0;
         while(getline(file1,line1))cnta++;
         while(getline(file2,line2))cntb++;
         return cntb-cnta<=1;
     };
     bool check = compareFiles("output.txt","expected.txt");
     if (check) cerr<<"ACCEPTED\n";
     else cerr<<"WRONG ANSWER!\n";
}
#else
#endif



 

Compilation message (stderr)

bitaro.cpp: In function 'void setIO(std::string)':
bitaro.cpp:33:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:34:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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