Submission #1108060

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108060		kiethm07	Bitaro’s Party (JOI18_bitaro)	C++11	100 / 100	1060 ms	92620 KiB

bitaro

#include <bits/stdc++.h>

#define pii pair<int,int>
#define iii pair<int,pii>
#define fi first
#define se second

#define vi vector<int>
#define all(x) x.begin(),x.end()

#define TEXT "a"

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

const int inf = 1e9 + 7;
const ld eps = 1e-8;
const double pi = acos(-1);
const int N = 1e5 + 5;
const int BLOCK = 100;

vector<int> a[N];
bool del[N];
int n,m,q;
int dp[N];
bool used[N];
pair<int,int> f[N][BLOCK];
int sz[N];

int cal(int u){
    if (dp[u] != -inf) return dp[u];
    dp[u] = del[u] ? -1 : 0;
    for (int v : a[u]){
        int f = cal(v);
        if (f != -1) dp[u] = max(dp[u], f + 1);
    }
    return dp[u];
}

void precompute(){
    for (int u = 1; u <= n; u++){
        priority_queue<pii> pq;
        for (int v : a[u]){
            for (int i = 0; i < sz[v]; i++) pq.push(f[v][i]);
        }
        vector<int> tmp;
        while(!pq.empty() && sz[u] < BLOCK){
            pii t = pq.top();
            pq.pop();
            if (t.fi == -1) break;
            if (used[t.se] == 0){
                used[t.se] = 1;
                tmp.push_back(t.se);
            }
            else continue;
            t.fi++;
            f[u][sz[u]++] = t;
        }
        if (sz[u] < BLOCK) f[u][sz[u]++] = pii(0,u);
        for (int i : tmp) used[i] = 0;
    }
}

void heavy(int str, vector<int>& v){
    for (int i = 1; i <= n; i++) dp[i] = -inf;
    for (int i : v) del[i] = 1;
    cout << cal(str) << "\n";
    for (int i : v) del[i] = 0;
}

void light(int str, vector<int>& v){
    int i = 0;
    for (int i : v) used[i] = 1;
    int res = -1;
    for (int i = 0; i < sz[str]; i++){
        int dis = f[str][i].fi;
        int id = f[str][i].se;
        if (used[id]) continue;
        res = dis;
        break;
    }
    for (int i : v) used[i] = 0;
    cout << res << "\n";
}

int main(){
    cin.tie(0) -> sync_with_stdio(0);
    if (fopen(TEXT".inp","r")){
        freopen(TEXT".inp","r",stdin);
        freopen(TEXT".out","w",stdout);
    }
    cin >> n >> m >> q;
    for (int i = 1; i <= m; i++){
        int u,v;
        cin >> u >> v;
        a[v].push_back(u);
    }
    precompute();
//    for (int u = 1; u <= n; u++) cout << u << " " << sz[u] << "\n";
    while(q--){
        int str;
        cin >> str;
        int num;
        cin >> num;
        vector<int> v(num);
        for (int& i : v) cin >> i;
        if (v.size() >= BLOCK) heavy(str,v);
        else light(str,v);
    }
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'void light(int, std::vector<int>&)':
bitaro.cpp:75:9: warning: unused variable 'i' [-Wunused-variable]
   75 |     int i = 0;
      |         ^
bitaro.cpp: In function 'int main()':
bitaro.cpp:92:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |         freopen(TEXT".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:93:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         freopen(TEXT".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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