Submission #90154

#	Time	Username	Problem	Language	Result	Execution time	Memory
90154		mirbek01	Biochips (IZhO12_biochips)	C++17	0 / 100	16 ms	20728 KiB

biochips

# include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 2;

int n, m, rt, a[N], tin[N], tout[N], timer, cur;
long long dp1[505][N], dp2[505][N], pref[N], suff[N], x[N];
vector <int> g[N];

void dfs1(int v){
      tin[v] = ++  timer;
      for(int to : g[v]){
            dfs1(to);
      }
      tout[v] = timer;
}

void dfs(int v){
      for(int to : g[v]){
            dfs(to);
      }
      if(cur >= 3){
            dp1[cur][tout[v]] = max(dp1[cur][tout[v]], dp1[cur - 2][tin[v] - 1] + dp2[cur - 2][tout[v] + 1] + x[v]);
            dp2[cur][tin[v]] = max(dp2[cur][tin[v]], dp1[cur - 2][tin[v] - 1] + dp2[cur - 2][tout[v] + 1] + x[v]);
      } else {
            dp1[cur][tout[v]] = max(dp1[cur][tout[v]], max(dp1[cur - 1][tin[v] - 1], dp2[cur - 1][tout[v] + 1]) + x[v]);
            dp2[cur][tin[v]] = max(dp2[cur][tin[v]], max(dp1[cur - 1][tin[v] - 1], dp2[cur - 1][tout[v] + 1]) + x[v]);
      }
}

int main(){
      cin >> n >> m;

      for(int i = 1; i <= n; i ++){
            int p;
            cin >> p >> x[i];
            if(!p)
                  rt = i;
            else {
                  g[p].push_back(i);
            }
      }

      dfs1(rt);

      for(int i = 0; i <= m; i ++){
            for(int j = 0; j < N; j ++)
                  dp1[i][j] = dp2[i][j] = -1e18;
      }

      for(int i = 1; i <= n; i ++){
            dp1[1][tout[i]] = max(x[i], dp1[1][tout[i]]);
            dp2[1][tin[i]] = max(x[i], dp2[1][tin[i]]);
      }

      for(int i = 2; i <= m; i ++){
            cur = i;
            for(int j = 1; j <= n; j ++)
                  dp1[i - 1][j] = max(dp1[i - 1][j - 1], dp1[i - 1][j]);
            for(int j = n; j >= 1; j --)
                  dp2[i - 1][j] = max(dp2[i - 1][j + 1], dp2[i - 1][j]);
            dfs(rt);
      }

      long long ans = 0;

      for(int i = 1; i <= n; i ++)
            ans = max(ans, dp1[m][i]);

      cout << ans << endl;
}

• Subtask 1: 0 / 100