oj.uz

답안 #868036

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
868036 2023-10-30T09:31:48 Z wakandaaa Chase (CEOI17_chase) C++17
100 / 100
 255 ms 255064 KB 
#include <bits/stdc++.h>
#define int long long

using namespace std;

#define file "chase"

#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()

#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}

const int N = 1e5 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;

template<class X, class Y> bool mini(X &a, Y b) {
    return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
    return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
    if (a < 0) a += mod;
}

int n, k;
vector<int> adj[N];
int a[N];
int f[N][105][2];
/*
f[u][i][0] : best value
f[u][i][1] : second-best value for rerooting
*/
int sum[N];
int tmp[N][105];

int res = 0;

void dfsF(int u, int p) {
    for (int v : adj[u]) if (v != p) {
        dfsF(v, u);
        for (int i = 1; i <= k; ++i) {
            int d = max(f[v][i][0], f[v][i - 1][0] + sum[v] - a[u]);
            if (d > f[u][i][0]) f[u][i][1] = f[u][i][0], f[u][i][0] = d;
            else maxi(f[u][i][1], d);
        }
    }
}

void dfsG(int u, int p) {
    for (int i = 1; i <= k; ++i) {
        maxi(res, f[u][i][0]);
        maxi(res, f[u][i - 1][0] + sum[u]);
    }
    for (int v : adj[u]) if (v != p) {
        // save changes
        for (int i = 1; i <= k; ++i) tmp[u][i] = f[u][i][0];

        // remove contribution
        for (int i = 1; i <= k; ++i) {
            int d = max(f[v][i][0], f[v][i - 1][0] + sum[v] - a[u]);
            if (f[u][i][0] == d) f[u][i][0] = f[u][i][1];            
        }

        // reroot
        for (int i = 1; i <= k; ++i) {
            int d = max(f[u][i][0], f[u][i - 1][0] + sum[u] - a[v]);
            if (d > f[v][i][0]) f[v][i][1] = f[v][i][0], f[v][i][0] = d;
            else maxi(f[v][i][1], d);
        }
        dfsG(v, u);

        // rollback changes
        for (int i = 1; i <= k; ++i) f[u][i][0] = tmp[u][i];

    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);

    cin >> n >> k;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    for (int i = 1; i < n; ++i) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    for (int u = 1; u <= n; ++u) {
        for (int v : adj[u]) sum[u] += a[v];
    }
    
    dfsF(1, 0);
    dfsG(1, 0);

    cout << res;

    return 0;
}

/*
12 2
2 3 3 8 1 5 6 7 8 3 5 4
2 1
2 7
3 4
4 7
7 6
5 6
6 8
6 9
7 10
10 11
10 12

36
*/

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4440 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4544 KB Output is correct
6 Correct 1 ms 4440 KB Output is correct

Subtask #2
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4440 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4544 KB Output is correct
6 Correct 1 ms 4440 KB Output is correct
7 Correct 3 ms 8540 KB Output is correct
8 Correct 2 ms 8540 KB Output is correct
9 Correct 2 ms 6232 KB Output is correct
10 Correct 3 ms 8284 KB Output is correct
11 Correct 2 ms 8400 KB Output is correct
12 Correct 2 ms 8284 KB Output is correct

Subtask #3
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 227 ms 221548 KB Output is correct
2 Correct 217 ms 221012 KB Output is correct
3 Correct 137 ms 176820 KB Output is correct
4 Correct 139 ms 255064 KB Output is correct
5 Correct 248 ms 254800 KB Output is correct
6 Correct 252 ms 254804 KB Output is correct
7 Correct 255 ms 254860 KB Output is correct

Subtask #4
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4440 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4544 KB Output is correct
6 Correct 1 ms 4440 KB Output is correct
7 Correct 3 ms 8540 KB Output is correct
8 Correct 2 ms 8540 KB Output is correct
9 Correct 2 ms 6232 KB Output is correct
10 Correct 3 ms 8284 KB Output is correct
11 Correct 2 ms 8400 KB Output is correct
12 Correct 2 ms 8284 KB Output is correct
13 Correct 227 ms 221548 KB Output is correct
14 Correct 217 ms 221012 KB Output is correct
15 Correct 137 ms 176820 KB Output is correct
16 Correct 139 ms 255064 KB Output is correct
17 Correct 248 ms 254800 KB Output is correct
18 Correct 252 ms 254804 KB Output is correct
19 Correct 255 ms 254860 KB Output is correct
20 Correct 249 ms 254888 KB Output is correct
21 Correct 34 ms 11088 KB Output is correct
22 Correct 249 ms 254804 KB Output is correct
23 Correct 129 ms 254800 KB Output is correct
24 Correct 247 ms 254712 KB Output is correct
25 Correct 135 ms 174272 KB Output is correct
26 Correct 214 ms 221288 KB Output is correct
27 Correct 215 ms 221268 KB Output is correct