Submission #672218

#	Time	Username	Problem	Language	Result	Execution time	Memory
672218		Alihan_8	Biochips (IZhO12_biochips)	C++17	20 / 100	394 ms	524288 KiB

biochips

#include <bits/stdc++.h>
// include <ext/pb_ds/assoc_container.hpp>
// include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;
using namespace std;
#define all(x) x.begin(), x.end()
#define pb push_back
// define ordered_set tree<int,null_type,less_equal<int>,rb_tree_tag,tree_order_statistics_node_update>
#define mpr make_pair
#define ln '\n'
void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
#define int long long
const int N = 2e5+1, M = 501;
vector <int> g[N];
int val[N], dp[N][M], m;
void chmax(int &l, int r){l = max(l, r);};
void dfs(int n){
    vector <int> _list;
    dp[n][1] = val[n];
    for ( auto to: g[n] ){
        dfs(to);
        for ( int i = 1; i <= m; i++ ){
            if ( _list.empty() ) continue;
            chmax(dp[to][i], dp[_list.back()][i-1]+val[to]);
            chmax(dp[to][i], dp[_list.back()][i]);
        }
        _list.pb(to);
    }
    if ( !_list.empty() ){
        for ( int i = 1; i <= m; i++ ){
            chmax(dp[n][i], dp[_list.back()][i]);
        }
    }
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n; cin >> n >> m;
    int root = -1;
    for ( int i = 1; i <= n; i++ ){
        int x; cin >> x >> val[i];
        if ( !x ){
            root = i;
            continue;
        }
        g[x].pb(i);
    }
    dfs(root);
    cout << dp[root][m];

    cout << '\n';
}

Compilation message (stderr)

biochips.cpp: In function 'void IO(std::string)':
biochips.cpp:11:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 | void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
biochips.cpp:11:70: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 | void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 100