Submission #2708430


Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define int long long int

vector<int> odd, even;
vector<int> prime_Lst;

template<typename T>
class Maxflow
{
    struct edge { int to; T cap; int rev; };
    std::vector<std::vector<edge> > edges;
    std::vector<int> level;
    std::vector<int> iter;
    std::vector<int> used;

    void bfs(int s)
    {
        level = std::vector<int>(edges.size(), -1);
        std::queue<int> q;
        level[s] = 0;
        q.push(s);
        while (!q.empty())
        {
            int v = q.front();
            q.pop();
            for (edge &e : edges[v])
            {
                if (e.cap > 0 && level[e.to] < 0)
                {
                    level[e.to] = level[v] + 1;
                    q.push(e.to);
                }
            }
        }
    }

    T dfs_d(int v, int goal, T f)
    {
        if (v == goal) return f;
        for (int &i = iter[v]; i < (int)edges[v].size(); i++)
        {
            edge &e = edges[v][i];
            if (e.cap > 0 && level[v] < level[e.to])
            {
                T d = dfs_d(e.to, goal, std::min(f, e.cap));
                if (d > 0)
                {
                    e.cap -= d;
                    edges[e.to][e.rev].cap += d;
                    return d;
                }
            }
        }
        return 0;
    }

    T dfs_ff(int v, int goal, T f)
    {
        if (v == goal) return f;
        used[v] = true;
        for (int i = 0; i < (int)edges[v].size(); i++)
        {
            edge &e = edges[v][i];
            if (e.cap > 0 && !used[e.to])
            {
                T d = dfs_ff(e.to, goal, std::min(f, e.cap));
                if (d > 0)
                {
                    e.cap -= d;
                    edges[e.to][e.rev].cap += d;
                    return d;
                }
            }
        }
        return 0;
    }

public:
    Maxflow(int N) { edges.resize(N); }
    void add_edge(int from, int to, T capacity)
    {
        edges[from].push_back(edge{to, capacity, (int)edges[to].size()});
        edges[to].push_back(edge{from, (T)0, (int)edges[from].size() - 1});
    }

    T Dinic(int s, int t)
    {
        constexpr T INF = std::numeric_limits<T>::max();
        T flow = 0;
        while (true)
        {
            bfs(s);
            if (level[t] < 0) return flow;
            iter = std::vector<int>(edges.size(), 0);
            T f;
            while ((f = dfs_d(s, t, INF)) > 0) flow += f;
        }
    }

    T FF(int s, int t)
    {
        constexpr T INF = std::numeric_limits<T>::max();
        T flow = 0;
        while (true)
        {
            used = std::vector<int>(edges.size(), 0);
            T f = dfs_ff(s, t, INF);
            if (f == 0) return flow;
            flow += f;
        }
    }
};

void find_prime(int t)
{
    vector<bool> ok(t+1, true);
    ok[0] = ok[1] = false;
    for (int i=2; i*i<=t; i++)
    {
        if (ok[i] && i>2) prime_Lst.push_back(i);
        for (int j=i; j<=t; j += i) ok[j] = false;
    }
}

signed main()
{
    int len;
    cin >> len;
    int tmp = -1;
    for (int i=0; i<len; i++)
    {
        cin >> tmp;
        if (tmp&1)
        {
            if (odd.size() == 0 || odd.back() != tmp)
            {
                odd.push_back(tmp);
            }
            else
            {
                odd.pop_back();
            }
            even.push_back(tmp+1);
        }
        else
        {
            if (even.size() == 0 || even.back() != tmp)
            {
                even.push_back(tmp);
            }
            else
            {
                even.pop_back();
            }
            odd.push_back(tmp+1);
        }
    }

    find_prime(len);

    int N = odd.size(), M = even.size();
    Maxflow<int> flow(1+N+M+1);
    for (int i=1; i<=N; i++) flow.add_edge(0, i, 1);
    for (int i=1; i<=M; i++) flow.add_edge(N+i, 1+N+M, 1);
    for (int i=1; i<=N; i++)
    {
        for (int j=1; j<=M; j++)
        {
            if (binary_search(prime_Lst.begin(), prime_Lst.end(), abs(odd[i-1] - even[j-1]))) flow.add_edge(i, N+j, 1);
        }
    }
    int res = flow.FF(0, 1+N+M);
    N -= res; M -= res;
    
    res += N+M;
    if (N&1) res++;
    cout << res << endl;
    return 0;
}

Submission Info

Submission Time
Task F - Prime Flip
User hitonanode
Language C++14 (GCC 5.4.1)
Score 0
Code Size 4431 Byte
Status WA
Exec Time 2 ms
Memory 256 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 0 / 1200
Status
AC × 3
AC × 16
WA × 59
Set Name Test Cases
Sample 0_00.txt, 0_01.txt, 0_02.txt
All 0_00.txt, 0_01.txt, 0_02.txt, 1_00.txt, 1_01.txt, 1_02.txt, 1_03.txt, 1_04.txt, 1_05.txt, 1_06.txt, 1_07.txt, 1_08.txt, 1_09.txt, 1_10.txt, 1_11.txt, 1_12.txt, 1_13.txt, 1_14.txt, 1_15.txt, 1_16.txt, 1_17.txt, 1_18.txt, 1_19.txt, 1_20.txt, 1_21.txt, 1_22.txt, 1_23.txt, 1_24.txt, 1_25.txt, 1_26.txt, 1_27.txt, 1_28.txt, 1_29.txt, 1_30.txt, 1_31.txt, 1_32.txt, 1_33.txt, 1_34.txt, 1_35.txt, 1_36.txt, 1_37.txt, 1_38.txt, 1_39.txt, 1_40.txt, 1_41.txt, 1_42.txt, 1_43.txt, 1_44.txt, 1_45.txt, 1_46.txt, 1_47.txt, 1_48.txt, 1_49.txt, 1_50.txt, 1_51.txt, 1_52.txt, 1_53.txt, 1_54.txt, 1_55.txt, 1_56.txt, 1_57.txt, 1_58.txt, 1_59.txt, 1_60.txt, 1_61.txt, 1_62.txt, 1_63.txt, 1_64.txt, 1_65.txt, 1_66.txt, 1_67.txt, 1_68.txt, 1_69.txt, 1_70.txt, 1_71.txt
Case Name Status Exec Time Memory
0_00.txt AC 1 ms 256 KB
0_01.txt AC 1 ms 256 KB
0_02.txt AC 1 ms 256 KB
1_00.txt AC 1 ms 256 KB
1_01.txt AC 1 ms 256 KB
1_02.txt AC 1 ms 256 KB
1_03.txt AC 2 ms 256 KB
1_04.txt AC 1 ms 256 KB
1_05.txt AC 1 ms 256 KB
1_06.txt AC 1 ms 256 KB
1_07.txt WA 1 ms 256 KB
1_08.txt WA 1 ms 256 KB
1_09.txt WA 1 ms 256 KB
1_10.txt WA 1 ms 256 KB
1_11.txt WA 1 ms 256 KB
1_12.txt WA 1 ms 256 KB
1_13.txt WA 1 ms 256 KB
1_14.txt WA 1 ms 256 KB
1_15.txt WA 1 ms 256 KB
1_16.txt WA 1 ms 256 KB
1_17.txt WA 1 ms 256 KB
1_18.txt WA 1 ms 256 KB
1_19.txt WA 1 ms 256 KB
1_20.txt WA 1 ms 256 KB
1_21.txt WA 1 ms 256 KB
1_22.txt WA 1 ms 256 KB
1_23.txt WA 1 ms 256 KB
1_24.txt WA 1 ms 256 KB
1_25.txt AC 1 ms 256 KB
1_26.txt WA 1 ms 256 KB
1_27.txt WA 1 ms 256 KB
1_28.txt AC 1 ms 256 KB
1_29.txt WA 1 ms 256 KB
1_30.txt WA 1 ms 256 KB
1_31.txt WA 1 ms 256 KB
1_32.txt WA 1 ms 256 KB
1_33.txt AC 1 ms 256 KB
1_34.txt AC 1 ms 256 KB
1_35.txt WA 1 ms 256 KB
1_36.txt AC 1 ms 256 KB
1_37.txt WA 1 ms 256 KB
1_38.txt WA 1 ms 256 KB
1_39.txt AC 1 ms 256 KB
1_40.txt WA 1 ms 256 KB
1_41.txt WA 1 ms 256 KB
1_42.txt WA 1 ms 256 KB
1_43.txt WA 1 ms 256 KB
1_44.txt WA 1 ms 256 KB
1_45.txt WA 1 ms 256 KB
1_46.txt WA 1 ms 256 KB
1_47.txt WA 1 ms 256 KB
1_48.txt WA 1 ms 256 KB
1_49.txt WA 1 ms 256 KB
1_50.txt WA 1 ms 256 KB
1_51.txt WA 1 ms 256 KB
1_52.txt WA 1 ms 256 KB
1_53.txt WA 1 ms 256 KB
1_54.txt WA 1 ms 256 KB
1_55.txt WA 1 ms 256 KB
1_56.txt WA 1 ms 256 KB
1_57.txt WA 1 ms 256 KB
1_58.txt WA 1 ms 256 KB
1_59.txt WA 1 ms 256 KB
1_60.txt WA 1 ms 256 KB
1_61.txt WA 1 ms 256 KB
1_62.txt WA 1 ms 256 KB
1_63.txt WA 1 ms 256 KB
1_64.txt WA 1 ms 256 KB
1_65.txt WA 1 ms 256 KB
1_66.txt WA 1 ms 256 KB
1_67.txt WA 1 ms 256 KB
1_68.txt WA 1 ms 256 KB
1_69.txt WA 1 ms 256 KB
1_70.txt WA 1 ms 256 KB
1_71.txt WA 1 ms 256 KB