Submission #723810

#	Time	Username	Problem	Language	Result	Execution time	Memory
723810		Mr_Husanboy	Magic Tree (CEOI19_magictree)	C++17	61 / 100	1121 ms	1048576 KiB

magictree

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
const int inf = 1e9;

template<typename T>
int len(T &a){
    return a.size();
}

struct Segtree{
    struct node{
        int mx = 0;
        void set(int x){
            mx = max(mx, x);
        }
        node(int x){mx = x;}
        node(){mx = 0;};
    };

    node merge(node a, node b){
        return node(max(a.mx, b.mx));
    }

    vector<node> t;
    int n;
    void init(int _n){
        n = _n;
        t.resize(4 * n, node());
    }

    void upd(int x, int lx, int rx, int ind, int val){
        if(lx == rx){
            t[x].set(val); return;
        }
        int m = (lx + rx) / 2;
        if(ind <= m){
            upd(x * 2, lx, m, ind, val);
        }else
            upd(x * 2 + 1, m + 1, rx, ind, val);
        t[x] = merge(t[x * 2], t[x * 2 + 1]);
    }

    node get(int x, int lx, int rx, int l, int r){
        if(l <= lx && rx <= r) return t[x];
        if(r < lx || rx < l){
            return {0};
        }
        int m = (lx + rx) / 2;
        return merge(get(x * 2, lx, m, l, r), get(x * 2 + 1, m + 1, rx, l, r));
    }

    void upd(int ind, int val){
        upd(1, 0, n - 1, ind, val);
    }

    node get(int l, int r){
        return get(1, 0, n - 1, l, r);
    }
};

void sub3(int &n, int &m, int &k, vector<int> p,
    vector<int> &v, vector<int> &day, vector<int> &cost){
    //cout << "start" << endl;
    for(int i = 1; i < n; i ++){
        if(p[i] != i - 1) return;
    }
    for(int i = 0; i < m; i ++){
        if(cost[i] != 1) return;
    }
    vector<int> fr(n);
    for(int i = 0; i < m; i ++){
        fr[v[i]] = day[i];
    }
    Segtree t; t.init(k + 1);
    int ans = 0;
    for(int i = n - 1; i > 0; i --){
        if(fr[i] == 0) continue;
        int mx = t.get(1, fr[i]).mx + 1;
        ans = max(ans, mx);
        t.upd(fr[i], mx);
    }
    cout << ans; exit(0); 
    cout << endl;
}

void sub2(int &n, int &m, int &k, vector<int> p,
    vector<int> &v, vector<int> &day, vector<int> &cost){
    //cout << "start" << endl;
    vector<vector<int>> g(n);
    for(int i = 1; i < n; i ++){
        g[p[i]].push_back(i);
    }
    ll ans = 0;
    for(int i = 0; i < m; i ++){
        if(len(g[v[i]])){return;}
        ans += cost[i];
    }
    cout << ans; exit(0);

}


void sub5(int &n, int &m, int &k, vector<int> p,
    vector<int> &v, vector<int> &day, vector<int> &cost){
    //cout << "start" << endl;

    vector<vector<int>> ng(n);
    vector<int> np(n, -1);
    for(int i = 1; i < n; i ++){
        ng[p[i]].push_back(i);
    }
    vector<int> nfr(n);
    nfr[0] = 1;
    for(int i =0; i < m; i++){
        nfr[v[i]] = 1;
    }
    auto compress = [&](auto &compress, int i,int near)->void{
        for(auto u : ng[i]){
            if(nfr[u]) np[u] = near;
            if(nfr[u]){
                compress(compress, u, u);
            }else
                compress(compress, u, near);
        }
    };
    vector<int> id(n, -1);

    compress(compress, 0, 0);
    for(int i = 0; i < m; i ++){
        id[v[i]] = i + 1;
    } 
    id[0] = 0;
    //for(auto u : id) cout << u << ' '; cout << endl;
    vector<vector<int>> g(m + 1);
    for(int i = 0; i < n; i ++){
        if(np[i] == -1) continue;
        g[id[np[i]]].push_back(id[i]);
    }
    // for(int i = 0; i < n; i ++){
    //     if(id[i] == -1) continue;
    //     cout << id[i] << ": ";
    //     for(auto u : g[id[i]]) cout << u << ' ';
    //         cout << endl;
    // }
    vector<ll> fr(n), c(n);
    for(int i = 0; i < m; i ++){
        fr[id[v[i]]] = day[i];
        c[id[v[i]]] = cost[i];
    }
    
    vector<vector<ll>> dp(m + 1, vector<ll> (k + 1, 0));
    auto dfs = [&](auto &dfs, int i)->void{
        //cout << i + 1 << endl;
        for(auto u : g[i]){
            dfs(dfs, u);
        }
        for(int j = 1; j <= k; j ++){
            ll s = (j == fr[i] ? c[i] : 0);
            for(auto u : g[i]){
                s += dp[u][j];
            }
            dp[i][j] = s;
            dp[i][j] = max(dp[i][j - 1], dp[i][j]);
        }
    };
    dfs(dfs, 0);
    //cout << "d" << endl;
    ll mx = 0;
    for(int i = 0; i <= m; i ++){
        for(int j = 1; j <= k; j++){
            mx = max(mx, dp[i][j]);
        }
    }
    cout << mx << endl;
    exit(0);
}

void solve(){
    int n, m, k; cin >> n >> m >> k;
    vector<int> p(n), v(m), day(m), cost(m);
    for(int i = 1; i < n; i ++){
        cin >> p[i]; p[i] --;
    }
    for(int i = 0; i < m; i ++){
        cin >> v[i] >> day[i] >> cost[i];
        v[i] --;
    }
    sub2(n, m, k, p, v, day, cost);
    sub3(n, m, k, p, v, day, cost);
    sub5(n, m, k, p, v, day, cost);
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    int testcases = 1;

    while(testcases --){
        solve();
        if(testcases) cout << '\n';
        #ifdef LOCAL
        else cout << '\n';
        cout << "__________________________" << endl;
        #endif
    }
    return 0;
}

• Subtask 1: 6 / 6
• Subtask 2: 3 / 3
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 16 / 16
• Subtask 6: 13 / 13
• Subtask 7: 0 / 22
• Subtask 8: 0 / 17