Submission #636368

#	Time	Username	Problem	Language	Result	Execution time	Memory
636368		Ez0zIOVgTsSgT	Biochips (IZhO12_biochips)	C++14	90 / 100	309 ms	405296 KiB

biochips

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

void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << h; if(sizeof...(t)) cerr << ", ";
    DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL

#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"

using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;

void setIO(string NAME = "") {
    cin.tie(0)->sync_with_stdio(0);
    if(sz(NAME)) {
        freopen((NAME + ".inp").c_str(),"r",stdin);
        freopen((NAME + ".out").c_str(),"w",stdout);
    }
}

tcT> bool ckmin(T&a, const T&b) {
    return b < a ? a=b,1 : 0; }
tcT> bool ckmax(T&a, const T&b) {
    return b > a ? a=b,1 : 0; }

const int MOD = 1e9 + 7;

const int MX = 2e5+5;
int N, M, par[MX], val[MX], rt, tin[MX], tout[MX], dp[MX][505], nodat[MX], tt;
vi adj[MX];

void dfs(int u) {
    nodat[tin[u] = ++tt] = u;
    each(v, adj[u]) {
        dfs(v);
    }
    tout[u] = tt;
}

void solve() {
    cin >> N >> M;
    FOR(i,1,N+1) {
        cin >> par[i] >> val[i];
        if(!par[i]) rt = i;
        else adj[par[i]].pb(i);
    }
    dfs(rt);
    memset(dp, -0x3f, sizeof dp);
    FOR(i,1,tt+2) {
        dp[i][0] = 0;
    }
    ROF(i,1,tt+1) {
        int u = nodat[i];
        int r = min(tout[u]+1, tt+1);
        FOR(j,1, M+1) {
            ckmax(dp[i][j], dp[i+1][j]);
            if(j>0) ckmax(dp[i][j], dp[r][j-1] + val[u]);
        }
    }
//    int ans = 0;
//    FOR(i,1,tt+1) ckmax(ans, dp[i][M]);
//    cout << ans << nl;
    cout << max(0, dp[1][M]) << nl;
}

int main() {
    setIO();

    int t=1;
    //cin>>t;
    while(t-->0) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

biochips.cpp: In function 'void setIO(std::string)':
biochips.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen((NAME + ".inp").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
biochips.cpp:38:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |         freopen((NAME + ".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 90 / 100