Submission #683892

#	Time	Username	Problem	Language	Result	Execution time	Memory
683892		KiriLL1ca	Biochips (IZhO12_biochips)	C++17	0 / 100	6 ms	5104 KiB

biochips

#include <bits/stdc++.h>
#define fr first
#define sc second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define pb push_back
#define pw(x) (1ll << x)
#define vec vector
#define sz(x) (int)((x).size())

using namespace std;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;

template <typename T> inline bool umin (T &a, const T &b) { if (a > b) { a = b; return 1; } return 0; }
template <typename T> inline bool umax (T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; }

const int N = 2e5 + 100;
const int M = 505;
vector <int> g[N];
int dp[N][M], siz[N], m, a[N];

inline void sizes (int v, int pr) { siz[v] = 1; for (auto u : g[v]) if (u != pr) sizes(u, v), siz[v] += siz[u]; }
inline void dfs (int v, int pr) {
        for (auto u : g[v]) if (u != pr) dfs(u, v);
        for (auto u : g[v]) if (u != pr) {
                for (int i = min(siz[v], m); i >= 0; --i) {
                        for (int j = min(siz[u], m - i); j >= 0 && i + j <= m; --j) {
                                umax(dp[v][i + j], dp[v][i] + dp[u][j]);
                        }
                }
        }
        umax(dp[v][1], a[v]);
}

inline void solve () {
        int n; cin >> n >> m;
        int rt = -1, p;
        for (int i = 0; i < n; ++i) {
                cin >> p >> a[i];
                if (!p) { rt = i; continue; }
                --p;
                g[i].pb(p); g[p].pb(i);
        }
        sizes(rt, rt); dfs(rt, rt);
        cout << dp[rt][m];
}

signed main() {
        ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
        #ifdef LOCAL
                freopen("input.txt", "r", stdin);
                freopen("output.txt", "w", stdout);
        #else
                freopen("biorobot.in", "r", stdin);
                freopen("biorobot.out", "w", stdout);
        #endif
        int t = 1; // cin >> t;
        while (t--) solve();
        return 0;
}

Compilation message (stderr)

biochips.cpp: In function 'int main()':
biochips.cpp:57:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |                 freopen("biorobot.in", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
biochips.cpp:58:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |                 freopen("biorobot.out", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 100