Submission #129111

#	Time	Username	Problem	Language	Result	Execution time	Memory
129111		SamAnd	Political Development (BOI17_politicaldevelopment)	C++17	100 / 100	161 ms	9336 KiB

politicaldevelopment

#include <bits/stdc++.h>
using namespace std;
const int N = 50004, K = 12;

int n, k;
vector<int> a[N];
bool c[N];
int q[N];

int f[1 << K];
int qq[1 << K];
void pre()
{
    for (int x = 1; x < (1 << k); ++x)
    {
        int yq = 0;
        for (int i = 0; i < k; ++i)
        {
            if ((x & (1 << i)))
            {
                f[x] = i;
                ++yq;
            }
        }
        qq[x] = yq;
    }
}

vector<int> v;
int xx[K];
bool dp[1 << K];
int stg()
{
    memset(xx, 0, sizeof xx);
    for (int i = 0; i < v.size(); ++i)
    {
        for (int j = 0; j < v.size(); ++j)
        {
            if (binary_search(a[v[i]].begin(), a[v[i]].end(), v[j]))
                xx[i] |= (1 << j);
        }
    }
    memset(dp, false, sizeof dp);
    dp[0] = true;
    int ans = 0;
    for (int x = 1; x < (1 << v.size()); ++x)
    {
        int i = f[x];
        int y = (x ^ (1 << i));
        if (dp[y] && (xx[i] & y) == y)
        {
            dp[x] = true;
            ans = max(ans, qq[x]);
        }
    }
    return ans;
}

int main()
{
    scanf("%d%d", &n, &k);
    for (int i = 0; i < n; ++i)
    {
        int s;
        scanf("%d", &s);
        while (s--)
        {
            int x;
            scanf("%d", &x);
            a[i].push_back(x);
        }
    }
    queue<int> s;
    for (int i = 0; i < n; ++i)
    {
        sort(a[i].begin(), a[i].end());
        q[i] = a[i].size();
        if (q[i] <= k)
            s.push(i);
    }
    pre();
    int ans = 1;
    while (1)
    {
        v.clear();
        int x;
        do
        {
            x = s.front();
            s.pop();
            if (s.empty())
            {
                cout << ans << endl;
                return 0;
            }
        } while (c[x]);
        for (int i = 0; i < a[x].size(); ++i)
        {
            int h = a[x][i];
            if (c[h])
                continue;
            v.push_back(h);
            --q[h];
            if (q[h] <= k)
                s.push(h);
        }
        ans = max(ans, stg() + 1);
        c[x] = true;
    }
    return 0;
}

Compilation message (stderr)

politicaldevelopment.cpp: In function 'int stg()':
politicaldevelopment.cpp:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < v.size(); ++i)
                     ~~^~~~~~~~~~
politicaldevelopment.cpp:37:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j = 0; j < v.size(); ++j)
                         ~~^~~~~~~~~~
politicaldevelopment.cpp: In function 'int main()':
politicaldevelopment.cpp:97:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < a[x].size(); ++i)
                         ~~^~~~~~~~~~~~~
politicaldevelopment.cpp:61:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &k);
     ~~~~~^~~~~~~~~~~~~~~~
politicaldevelopment.cpp:65:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &s);
         ~~~~~^~~~~~~~~~
politicaldevelopment.cpp:69:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", &x);
             ~~~~~^~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 38 / 38
• Subtask 5: 23 / 23