Submission #1007863

#	Time	Username	Problem	Language	Result	Execution time	Memory
1007863		n3rm1n	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	1115 ms	437332 KiB

bitaro

#include<bits/stdc++.h>
#define endl '\n'
#define ll int
using namespace std;
const int MAXN = 3e5 + 10;
void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}
int n, m, q;
int bracket;
vector < int > g[MAXN], grev[MAXN];
int tt, yy;
void read()
{
    cin >> n >> m >> q;
    bracket = sqrt(n);
    int from, to;
    for (int i = 1; i <= m; ++ i)
    {
        cin >> from >> to;
        g[from].push_back(to);
        grev[to].push_back(from);
    }
}


int marked[MAXN], dp[MAXN];
deque < pair < int, int > > opt[MAXN];
int c[MAXN], f[MAXN];
int used[MAXN];
deque < pair < int, int > > comb(deque < pair < int, int > > f, deque < pair < int, int > > s)
{
    vector < int > usedv;
    deque < pair < int, int > > q;
    while(f.size() && s.size() && q.size() <= bracket)
    {
        pair <int, int >  ft = f.front();
        pair < int, int > st = s.front();
        st.first ++;
        if(ft.first > st.first)
        {
            f.pop_front();
            if(!used[ft.second])
            {
                used[ft.second] = 1;
                usedv.push_back(ft.second);
                q.push_back(ft);
            }

        }
        else
        {
            s.pop_front();
            if(!used[st.second])
            {
                used[st.second] = 1;
                usedv.push_back(st.second);
                q.push_back(st);
            }
        }
    }
    while(f.size() && q.size() <= bracket)
    {
        pair <int, int >  ft = f.front();
        f.pop_front();
        if(!used[ft.second])
        {
            used[ft.second] = 1;
            usedv.push_back(ft.second);
            q.push_back(ft);
        }
    }
    while(s.size() && q.size() <= bracket)
    {
        pair <int, int >  st = s.front();
        st.first ++;
        s.pop_front();
        if(!used[st.second])
        {
            used[st.second] = 1;
            usedv.push_back(st.second);
            q.push_back(st);
        }
    }
    for (int i  = 0; i < usedv.size(); ++ i)
        used[usedv[i]] = 0;
    return q;
}
void precompute_small()
{
    for (int i = 1; i <= n; ++ i)
        opt[i].clear();

    for (int i = 1; i <= n; ++ i)
    {
        int apar;
        deque < pair < int, int > > qq;
        qq.push_back(make_pair(0, i));
        opt[i] = qq;
        for (int j = 0; j < grev[i].size(); ++ j)
        {
            apar = grev[i][j];
            opt[i] = comb(opt[i], opt[apar]);
        }
    }

    /*for (int i =1;i <= n; ++ i)
    {
        cout << "for i " << i << endl;
        for (int j = 0; j < opt[i].size(); ++ j)
            cout << " (" <<opt[i][j].first << "," << opt[i][j].second <<") ";
        cout <<endl;
    }*/
}
void solve_small()
{
    // cout << "is small" << endl;
    int maxx = -1;
    for (int i = 0; i < opt[tt].size(); ++ i)
    {
        if(!marked[opt[tt][i].second])
            maxx = max(maxx, opt[tt][i].first);
    }

    cout << maxx << endl;
}
void solve_big()
{
    //cout << "is big" << endl;
    for (int i = 1; i <= n; ++ i)
        dp[i] = -1;
    int maxx = -1, cnt = 0;
    for (int i = tt; i >= 1; -- i)
    {
        if(i == tt)
        {
            dp[i] = 0;
            if(!marked[i])
                maxx = 0;
            continue;
        }
        for (int j = 0; j < g[i].size(); ++ j)
        {
            int nb = g[i][j];
            if(dp[nb] != -1)dp[i] = max(dp[i], dp[nb] + 1);
        }
        /// cout << dp[i] << endl;
        if(!marked[i])maxx = max(maxx, dp[i]);
    }
    cout << maxx << endl;
}
int main()
{
    speed();

    read();
    precompute_small();
    while(q --)
    {
        cin >> tt >> yy;

        for (int i = 1; i <= yy; ++ i)
        {
            cin >> c[i];
            marked[c[i]] = 1;
        }
        if(yy  > bracket)
        {
            solve_big();
        }
        else solve_small();
        for (int i = 1; i <= yy; ++ i)
        {
            marked[c[i]] = 0;
        }
    }
    return 0;
}
/***
12 17 1
1 2
2 3
3 4
1 5
2 6
3 7
4 8
5 6
6 7
7 8
5 9
6 10
7 11
8 12
9 10
10 11
11 12
6 3 1 7 12

5 6 3
1 2
2 4
3 4
1 3
3 5
4 5
4 1 1
5 2 2 3
2 3 1 4 5

10 1 3
1 2
1 0
2 1 2
3 1 2
/*/

Compilation message (stderr)

bitaro.cpp: In function 'std::deque<std::pair<int, int> > comb(std::deque<std::pair<int, int> >, std::deque<std::pair<int, int> >)':
bitaro.cpp:38:44: warning: comparison of integer expressions of different signedness: 'std::deque<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   38 |     while(f.size() && s.size() && q.size() <= bracket)
      |                                   ~~~~~~~~~^~~~~~~~~~
bitaro.cpp:65:32: warning: comparison of integer expressions of different signedness: 'std::deque<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   65 |     while(f.size() && q.size() <= bracket)
      |                       ~~~~~~~~~^~~~~~~~~~
bitaro.cpp:76:32: warning: comparison of integer expressions of different signedness: 'std::deque<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   76 |     while(s.size() && q.size() <= bracket)
      |                       ~~~~~~~~~^~~~~~~~~~
bitaro.cpp:88:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |     for (int i  = 0; i < usedv.size(); ++ i)
      |                      ~~^~~~~~~~~~~~~~
bitaro.cpp: In function 'void precompute_small()':
bitaro.cpp:103:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |         for (int j = 0; j < grev[i].size(); ++ j)
      |                         ~~^~~~~~~~~~~~~~~~
bitaro.cpp: In function 'void solve_small()':
bitaro.cpp:122:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |     for (int i = 0; i < opt[tt].size(); ++ i)
      |                     ~~^~~~~~~~~~~~~~~~
bitaro.cpp: In function 'void solve_big()':
bitaro.cpp:145:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  145 |         for (int j = 0; j < g[i].size(); ++ j)
      |                         ~~^~~~~~~~~~~~~
bitaro.cpp:135:20: warning: unused variable 'cnt' [-Wunused-variable]
  135 |     int maxx = -1, cnt = 0;
      |                    ^~~

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