제출 #143478

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
143478		popovicirobert	Chase (CEOI17_chase)	C++14	0 / 100	333 ms	169104 KiB

chase

#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long



/*const int MOD = ;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}

inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}

inline int inv(int x) {
    return lgput(x, MOD - 2);
}*/

/*int fact[], invfact[];

inline void prec(int n) {
    fact[0] = 1;
    for(int i = 1; i <= n; i++) {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    invfact[n] = lgput(fact[n], MOD - 2);
    for(int i = n - 1; i >= 0; i--) {
        invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
    }
}

inline int comb(int n, int k) {
    if(n < k) return 0;
    return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}*/

using namespace std;

const ll INF = 1e18;
const int MAXN = (int) 1e5;

vector <int> g[MAXN + 1];
int vals[MAXN + 1], v;
ll sum[MAXN + 1];

ll up[MAXN + 1][101], down[MAXN + 1][101];
ll ans = 0;

void dfs(int nod, int par) {

    up[nod][0] = 0;
    up[nod][1] = sum[nod];
    down[nod][0] = 0;
    down[nod][1] = sum[nod] - vals[par];

    for(auto it : g[nod]) {
        if(it != par) {
            dfs(it, nod);
            ll mx = 0;
            for(int i = 0; i <= v; i++) {
                mx = max(mx, up[nod][i]);
                ans = max(ans, mx + down[it][v - i]);
            }
            for(int i = 0; i <= v; i++) {
                up[nod][i] = max(up[nod][i], up[it][i]);
                if(i > 0) {
                    up[nod][i] = max(up[nod][i], up[it][i - 1] + sum[nod] - vals[it]);
                }
                down[nod][i] = max(down[nod][i], down[it][i]);
                if(i > 0) {
                    down[nod][i] = max(down[nod][i], down[it][i - 1] + sum[nod] - vals[par]);
                }
            }
        }
    }

    for(int i = 1; i <= v; i++) {
        up[nod][i] = max(up[nod][i], up[nod][i - 1]);
        down[nod][i] = max(down[nod][i], down[nod][i - 1]);
    }
    ans = max(ans, max(up[nod][v], down[nod][v] + vals[par]));
}


int main() {
#if 0
    ifstream cin("A.in");
    ofstream cout("A.out");
#endif
    int i, j, n;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n >> v;
    for(i = 1; i <= n; i++) {
        cin >> vals[i];
    }
    for(i = 1; i < n; i++) {
        int x, y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(i = 1; i <= n; i++) {
        for(auto it : g[i]) {
            sum[i] += vals[it];
        }
    }

    for(i = 1; i <= n; i++) {
        for(j = 0; j <= v; j++) {
            up[i][j] = down[i][j] = -INF;
        }
    }

    dfs(1, 0);

    cout << ans;

    return 0;
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 30