Submission #337138

#	Time	Username	Problem	Language	Result	Execution time	Memory
337138		nvmdava	Biochips (IZhO12_biochips)	C++17	100 / 100	363 ms	403308 KiB

biochips

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ff first
#define ss second
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 200'005;
const ll MOD = 1'000'000'007;
const int INF = 0x3f3f3f3f;

int dp[N][505];
vector<int> ch[N];
int cnt = 1, w[N], ww[N], l[N];

void dfs(int v){
    int t = cnt;
    for(auto& x : ch[v])
        dfs(x);
    ww[cnt] = w[v];
    l[cnt++] = t;

}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int n, m;
    cin>>n>>m;

    int root;

    for(int p, i = 1; i <= n; ++i){
        cin>>p>>w[i];
        if(p)
            ch[p].push_back(i);
        else
            root = i;
    }

    dfs(root);
    for(int i = 0; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
            dp[i][j] = -0x3f3f3f3f;
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
            dp[i][j] = max(dp[i - 1][j], dp[l[i] - 1][j - 1] + ww[i]);
    cout<<dp[n][m];
}

Compilation message (stderr)

biochips.cpp: In function 'int main()':
biochips.cpp:42:8: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
   42 |     dfs(root);
      |     ~~~^~~~~~

• Subtask 1: 100 / 100