Submission #1073662

#	Time	Username	Problem	Language	Result	Execution time	Memory
1073662		steveonalex	Friend (IOI14_friend)	C++17	69 / 100	26 ms	9048 KiB

friend

#include "friend.h"
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 1e5 + 69;
int n;
int a[N];
int p[N], q[N];


namespace Sub1{
    bool check(){
        return (n <= 10);
    }

    int solve(){
        bool graph[n][n];
        memset(graph, 0, sizeof graph);
        for(int i= 1; i<n; ++i){
            int j = p[i];
            if (q[i] == 0){
                graph[i][j] = graph[j][i] = 1;
            }
            else if (q[i] == 2) {
                for(int k = 0; k<i; ++k) graph[i][k] = graph[k][i] = graph[j][k];
                graph[i][j] = graph[j][i] = 1;
            }
            else{
                for(int k = 0; k<i; ++k) graph[i][k] = graph[k][i] = graph[j][k];
            }
        }

        int ans = 0;
        for(int mask = 0; mask < MASK(n); ++mask){
            int cur = 0;
            for(int j = 0; j< n; ++j) if (GETBIT(mask, j)) cur += a[j];

            bool check = true;
            for(int i = 0; i < n; ++i) if (GETBIT(mask, i))
            for(int j = 0; j<n; ++j) if (GETBIT(mask, j)) 
                if (graph[i][j]) check = false;

            if (check) maximize(ans, cur);
        }
        return ans;
    }
}


namespace Sub2{
    bool check(){
        for(int i = 1; i<n; ++i) if (q[i] != 1) return false;
        return true;
    }

    int solve(){
        int ans = 0;
        for(int i = 0; i<n; ++i) ans += a[i];
        return ans;
    }
}


namespace Sub3{
    bool check(){
        for(int i = 1; i<n; ++i) if (q[i] != 2) return false;
        return true;
    }

    int solve(){
        int ans = 0;
        for(int i = 0; i<n; ++i) maximize(ans, a[i]);
        return ans;
    }
}

namespace Sub4{
    bool check(){
        for(int i = 1; i<n; ++i) if (q[i] != 0) return false;
        return true;
    }

    vector<int> graph[N];
    int dp[N][2];

    void dfs(int u){
        dp[u][1] = a[u];
        for(int v: graph[u]){
            dfs(v);
            dp[u][0] += max(dp[v][0], dp[v][1]);
            dp[u][1] += dp[v][0];
        }
    }

    int solve(){
        for(int i= 1; i<n; ++i) graph[p[i]].push_back(i);

        dfs(0);
        return max(dp[0][0], dp[0][1]);
    }
}


namespace Sub5{
    bool check(){
        if (n > 1000) return false;
        for(int i = 1; i<n; ++i) if (q[i] == 2) return false;
        return true;
    }

    vector<int> graph[N];


    namespace Matching{
        const long N = 1e3 + 69, M = 1e6 + 69;
        long n = 0, m = 0;
        vector<pair<long, long>> graph[N];
        bool edgeOn[M], visited[N], saturated[N];
    
        void reset(){
            for(long i = 0; i<=n; ++i) {
                graph[i].clear();
                saturated[i] = visited[i] = 0;
            }
            for(long j = 0 ;j<=m; ++j) edgeOn[j] = 0;
            m = 0;
        }
    
        void add_edge(long u, long v){
            m++;
            graph[u].push_back({v, m});
            graph[v].push_back({u, m});
            if (!saturated[u] && !saturated[v]){
                saturated[u] = saturated[v] = edgeOn[m] = 1;
            }
        }
    
        void make_sure(){
            for(long i = 1; i<=n; ++i) shuffle(ALL(graph[i]), rng);
        }
    
        bool kuhn(long u, bool bit){
            visited[u] = true;
            if (!saturated[u] && bit) return true;
            for(auto v: graph[u]) if (!visited[v.first] && edgeOn[v.second] == bit){
                if (kuhn(v.first, !bit)){
                    saturated[u] = saturated[v.first] = 1;
                    edgeOn[v.second] ^= 1;
                    return true;
                }
            }
            return false;
        }
    
        long solve(){
            while(true){
                bool found = false;
                for(long j = 0; j<=n; ++j) visited[j] = 0;
                for(long i = 1; i<=n; ++i){
                    if (visited[i] || saturated[i]) continue;
                    found |= kuhn(i, 0);
                }
                if (!found) break;
            }
            long ans = 0;
            for(long i = 1; i<=m; ++i) ans += edgeOn[i];
            return ans;
        }
    }
    

    int solve(){
        vector<pair<int, int>> edge;
        vector<bool> color(n);
        for(int i = 1; i<n; ++i){
            int j = p[i];
            if (q[i] == 0){
                graph[i].push_back(j);
                graph[j].push_back(i);
                edge.push_back({i, j});
                color[i] = !color[j];
            }
            else{
                for(int k: graph[j]) {
                    if (color[k] != color[graph[j][0]]) exit(1);
                    graph[i].push_back(k);
                    graph[k].push_back(i);
                    edge.push_back({i, k});
                }
                color[i] = color[j];
            }
        }

        if (edge.size() > 1e6) exit(2);

        Matching::reset();
        Matching::n = n;
        for(pair<int, int> i: edge) Matching::add_edge(i.first, i.second);
        return n - Matching::solve();
    }
}

int findSample(int _n, int confidence[], int host[], int protocol[]){
    n = _n;
    for(int i = 0; i < n; ++i) a[i] = confidence[i];
    for(int i = 1; i<n; ++i){
        p[i] = host[i];
        q[i] = protocol[i];
    }

    if (Sub2::check()) return Sub2::solve();
    if (Sub3::check()) return Sub3::solve();
    if (Sub4::check()) return Sub4::solve();
    if (Sub1::check()) return Sub1::solve();
    if (Sub5::check()) return Sub5::solve();
    return -1;
}

// int main(void){
//     ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
//     clock_t start = clock();

    
 
//     cerr << "Time elapsed: " << clock() - start << " ms\n";
//     return 0;
// }

• Subtask 1: 11 / 11
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 19 / 19
• Subtask 5: 23 / 23
• Subtask 6: 0 / 31