Submission #523499

#	Time	Username	Problem	Language	Result	Execution time	Memory
523499		knightron0	Biochips (IZhO12_biochips)	C++14	0 / 100	6 ms	11212 KiB

biochips

#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define fr first
#define sc second
#define clr(a, x) memset(a, x, sizeof(a))
#define dbg(x) cout<<"("<<#x<<"): "<<x<<endl;
#define printvector(arr) for (auto it = arr.begin(); it != arr.end(); ++it) cout<<*it<<" "; cout<<endl;
#define all(v) v.begin(), v.end()
#define lcm(a, b) (a * b)/__gcd(a, b)
#define int long long int
#define printvecpairs(vec) for(auto it: vec) cout<<it.fr<<' '<<it.sc<<endl;
#define endl '\n'
#define float long double

const int MOD = 1e9 + 7;
const int INF = 2e15;
const int MAXN = 4e5 + 5;

vector<int> adj[MAXN];
int val[MAXN], timer = 1;
int tin[MAXN], tout[MAXN], et[4*MAXN];
bool iftin[4*MAXN];

void dfs(int s){
    tin[s] = timer;
    iftin[timer] = true;
    et[timer] = s;
    timer++;
    for(auto u: adj[s]){
        dfs(u);
    }
    tout[s] = timer;
    et[timer] = s;
    iftin[timer] = false;
    timer++;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    #ifdef LOCAL
    freopen("input.txt", "r", stdin);
    #endif
    int n, m;
    cin>>n>>m;
    int dp[(2*n)+3][2];
    int root = -1;
    clr(iftin, 0);
    for(int i= 1;i<=n;i++){
        int t1, t2;
        cin>>t1>>t2;
        val[i] = t2;
        if(t1 == 0){
            root = i;
            continue;
        } else {
            adj[t1].pb(i);
        }
    }
    dfs(root);
    dp[(2*n)+1][0] = 0;
    dp[(2*n)+1][1] = -INF;
    int ans = -INF;
    for(int i = 2*n;i>=1;i--){
        dp[i][0] = 0;
        for(int j = 1;j<=m;j++){
            if(iftin[i]){
                if(tout[et[i]] == 2*n && j != 1){
                    dp[i][j%2] = dp[i+1][j%2];
                    continue;
                }
                dp[i][j%2] = max(dp[i+1][j%2], dp[tout[et[i]]+1][(j-1)%2]+val[et[i]]);
            } else {
                dp[i][j%2] = dp[i+1][j%2];
            }
        }
        ans = max(ans, dp[i][m%2]);
    }
    cout<<ans<<endl;
    return 0;
}

• Subtask 1: 0 / 100