Submission #825511

#	Time	Username	Problem	Language	Result	Execution time	Memory
825511		Charizard2021	Biochips (IZhO12_biochips)	C++17	100 / 100	373 ms	400904 KiB

biochips

#include<bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define IOS ios::sync_with_stdio(false);; cin.tie(NULL)
void selfMax(long long& a, long long b){
    a = max(a, b);
}
void selfMin(long long& a, long long b){
    a = min(a, b);
}
template<typename T> istream& operator>>(istream& in, vector<T>& a) {for(auto &x : a) in >> x; return in;};
template<typename T1, typename T2> istream& operator>>(istream& in, pair<T1, T2>& x) {return in >> x.first >> x.second;}

template<typename T1, typename T2> ostream& operator<<(ostream& out, const pair<T1, T2>& x) {return out << x.first << ' ' << x.second;}
template<typename T> ostream& operator<<(ostream& out, vector<T>& a) {for(auto &x : a) out << x << ' '; return out;};
template<typename T> ostream& operator<<(ostream& out, vector<vector<T> >& a) {for(auto &x : a) out << x << '\n'; return out;};
template<typename T1, typename T2> ostream& operator<<(ostream& out, vector<pair<T1, T2> >& a) {for(auto &x : a) out << x << '\n'; return out;};

/*

Use DSU dsu(N);

*/
struct DSU {
	vector<long long> adj2;
	DSU(long long N) { adj2 = vector<long long>(N, -1); }

	// get representive component (uses path compression)
	long long get(long long x) { return adj2[x] < 0 ? x : adj2[x] = get(adj2[x]); }

	bool same_set(long long a, long long b) { return get(a) == get(b); }

	long long size(long long x) { return -adj2[get(x)]; }

	bool unite(long long x, long long y) {  // union by size
		x = get(x), y = get(y);
		if (x == y) return false;
		if (adj2[x] > adj2[y]) swap(x, y);
		adj2[x] += adj2[y]; adj2[y] = x;
		return true;
	}
};
/*

Run with Bit<long long> BIT

*/
template <class T> class BIT {
    private:
        long long size;
        vector<T> bit;
        vector<T> arr;
    public:
        BIT(long long size) : size(size), bit(size + 1), arr(size) {}
        void set(long long ind, long long val) { add(ind, val - arr[ind]); }
        void add(long long ind, long long val) {
            arr[ind] += val;
            ind++;
            for (; ind <= size; ind += ind & -ind) { bit[ind] += val; }
        }
        T pref_sum(long long ind) {
            ind++;
            T total = 0;
            for (; ind > 0; ind -= ind & -ind) { total += bit[ind]; }
            return total;
        }
};
/*

Change Comb for specific Seg tree probs, but run with Seg<long long> Seg;

*/
template<class T> struct Seg {
	const T ID = 1e18; T comb(T a, T b) { return min(a,b); }
	long long n; vector<T> seg;
	void init(long long _n) { n = _n; seg.assign(2*n,ID); }
	void pull(long long p) { seg[p] = comb(seg[2*p],seg[2*p+1]); }
	void upd(long long p, T val) {
		seg[p += n] = val; for (p /= 2; p; p /= 2) pull(p); }
	T query(long long l, long long r) {
		T ra = ID, rb = ID;
		for (l += n, r += n+1; l < r; l /= 2, r /= 2) {
			if (l&1) ra = comb(ra,seg[l++]);
			if (r&1) rb = comb(seg[--r],rb);
		}
		return comb(ra,rb);
	}
};
const int N = 200001;
const int M = 501;
vector<int> adj[N];
int dp[N][M];
int values[N];
int timeVal = 0;
int timeIn[N];
int timeOut[N];
int val[N];
void dfs(int u){
    timeVal++;
    timeIn[u] = timeVal;
    val[timeVal] = values[u];
    dp[timeVal][1] = values[u];
    for(int v : adj[u]){
        dfs(v);
    }
    timeOut[timeIn[u]] = timeVal;
}
int main(){
    int n, m;
    cin >> n >> m;
    int start = -1;
    for(int i = 1; i <= n; i++){
        int p;
        cin >> p;
        cin >> values[i];
        if(p == 0){
            start = i;
        }
        else{
            adj[p].push_back(i);
        }
    }
    dfs(start);
    int ans = 0;
    for(int i = timeVal; i >= 1; i--){
        for(int j = 1; j <= m; ++j){
            if(i + 1 <= timeVal){
                dp[i][j] = max(dp[i][j], dp[i + 1][j]);
            }
            if(timeOut[i] + 1 <= timeVal){
                dp[i][j] = max(dp[i][j] , dp[timeOut[i] + 1][j - 1] + val[i]);
            }
            if(j == m){
                ans = max(ans, dp[i][j]);
            }
        }
    }
    cout << ans << "\n";
}

• Subtask 1: 100 / 100