Submission #701646

#	Time	Username	Problem	Language	Result	Execution time	Memory
701646		hgmhc	Biochips (IZhO12_biochips)	C++17	100 / 100	475 ms	22348 KiB

biochips

#include <bits/stdc++.h>
using namespace std; using ii = pair<int,int>; using ll = long long;
#define rep(i,a,b) for (auto i = (a); i <= (b); ++i)
#define per(i,a,b) for (auto i = (b); i >= (a); --i)
#define all(x) begin(x), end(x)
#define siz(x) int((x).size())
#define Mup(x,y) x = max(x,y)
#define mup(x,y) x = min(x,y)
#define fi first
#define se second
#define dbg(...) fprintf(stderr,__VA_ARGS__)

const int N = 2e5+3, M = 503;
int n, m, a[N], r, sub[N];
vector<int> child[N];
vector<ll> dp[N];

void pre(int s = r, int e = 0) {
    sub[s] = 1;
    for (auto u : child[s]) if (u != e) {
        pre(u,s), sub[s] += sub[u];
    }
}
void solve(int s = r, int e = 0) {
    dp[s].resize(min(m,sub[s])+1,-1e18);
    dp[s][0] = 0;
    for (auto u : child[s]) if (u != e) {
        solve(u,s);
        per(x,1,min(m,sub[s])) rep(y,0,min(x,sub[u])) {
            Mup(dp[s][x],dp[u][y]+dp[s][x-y]);
        }
    }
    Mup(dp[s][1],ll(a[s]));
}

int main() {
    scanf("%d %d", &n, &m);
    rep(i,1,n) {
        int p; scanf("%d %d", &p, &a[i]);
        if (p == 0) r = i;
        else child[p].push_back(i);
    }
    pre(), solve();
    printf("%lld", dp[r][m]);
}

Compilation message (stderr)

biochips.cpp: In function 'int main()':
biochips.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
biochips.cpp:39:21: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         int p; scanf("%d %d", &p, &a[i]);
      |                ~~~~~^~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100