Submission #530612

#	Time	Username	Problem	Language	Result	Execution time	Memory
530612		Killer2501	Bitaro’s Party (JOI18_bitaro)	C++14	7 / 100	2100 ms	217180 KiB

bitaro

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ull unsigned long long
#define pb push_back
#define pll pair<ll, ll>
#define pii pair<int, int>
#define fi first
#define se second
using namespace std;
const int N = 2e5+5;
const int M = 250;
const int mod = 1e9+7;
const ll base = 75;
const int inf = 1e9;
int m, n, t, b[N], d[N], lab[N], q;
int k, a[N];
pii dp[N][M], cur[M];
int ans, tong;
vector<int> adj[N], g[N];
vector<int> vi;
string s[N];
bool vis[N];
ll pw(ll k, ll n)
{
    ll total = 1;
    for(; n; n >>= 1)
    {
        if(n&1)total = total * k % mod;
        k = k * k % mod;
    }
    return total;
}
void add(int &x, int y)
{
    x += y;
    if(x >= mod)x -= mod;
}
int findp(int u)
{
    return lab[u] < 0 ? u : lab[u] = findp(lab[u]);
}
void hop(int u, int v)
{
    u = findp(u);
    v = findp(v);
    if(u == v)return;
    if(lab[u] > lab[v])swap(u, v);
    lab[u] += lab[v];
    lab[v] = u;
}
bool cmp(const int& x, const int& y)
{
    return d[x] > d[y];
}
void fix(int l, int r)
{
    int i = 0, j = 0;
    while(i+j < M)
    {
        if(dp[l][i].fi+1 > dp[r][j].fi)
        {
            if(dp[l][i].fi == -1)break;
            cur[i+j].fi = dp[l][i].fi+1;
            cur[i+j].se = dp[l][i].se;
            ++i;
        }
        else
        {
            cur[i+j] = dp[r][j];
            ++j;
        }
    }
    for(int j = 0; j < M; j ++)
    {
        dp[r][j] = cur[j];
        cur[j].fi = -1;
    }
}
void sol()
{
    cin >> n >> m >> q;
    for(int i = 1; i <= m; i ++)
    {
        int x, y;
        cin >> x >> y;
        adj[y].pb(x);
        g[x].pb(y);
    }
    for(int j = 0; j < M; j ++)cur[j].fi = -1;
    for(int i = 1; i <= n; i ++)
    {
        for(int j = 1; j < M; j ++)dp[i][j].fi = -1;
        dp[i][0].se = 0;
        for(int v: adj[i])fix(v, i);
    }
    for(int u = 1; u <= n; u ++)
    {
        vis[u] = true;
        vi.pb(u);
        for(int v: adj[u])
        {
            for(int j = 0; j < M; j ++)
            {
                if(dp[v][j].fi == -1)break;
                d[dp[v][j].se] = max(d[dp[v][j].se], dp[v][j].fi+1);
                if(!vis[dp[v][j].se])
                {
                    vis[dp[v][j].se] = true;
                    vi.pb(dp[v][j].se);
                }
            }
        }
        sort(vi.begin(), vi.end(), cmp);
        for(int j = 0; j < min((int)vi.size(), M); j ++)
        {
            dp[u][j].fi = d[vi[j]];
            dp[u][j].se = vi[j];
        }
        for(int j = 0; j < (int)vi.size(); j ++)
        {
            vis[vi[j]] = false;
            d[vi[j]] = 0;
        }
    }
    while(q -- > 0)
    {
        cin >> k >> n;
        for(int i = 1; i <= n; i ++)
        {
            cin >> a[i];
            vis[a[i]] = true;
        }
        if(dp[k][0].fi == -1)cout << -1 << '\n';
        else
        {
            ans = -1;
            if(n >= M)
            {
                for(int u = 1; u <= k; u ++)
                {
                    if(vis[u])d[u] = -1;
                    else d[u] = 0;
                }
                for(int u = 1; u <= k; u ++)
                {
                    if(d[u] == -1)continue;
                    for(int v: g[u])d[v] = max(d[v], d[u]+1);
                }
                ans = d[k];

            }
            else
            {
                for(int i = 0; i < M; i ++)
                {
                    if(!vis[dp[k][i].se])
                    {
                        ans = dp[k][i].fi;
                        break;
                    }
                }
            }
            cout << ans << '\n';
        }
        for(int i = 1; i <= n; i ++)vis[a[i]] = false;
    }
}
int main()
{
    cin.tie(0);
    cout.tie(0);
    ios_base::sync_with_stdio(0);
    #define task "test"
    if(fopen(task".inp", "r"))
	{
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
	}
    int test = 1;
    //cin >> test;
    while(test -- > 0)sol();
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:177:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  177 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:178:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  178 |   freopen(task".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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