#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using T = tuple<ll, ll, ll>;
#define int long long
#define Base 41
#define sz(a) (int)a.size()
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define all(x) x.begin() , x.end()
#define pii pair<int , int>
#define fi first
#define se second
#define Lg(x) 31 - __builtin_clz(x)
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 5e2 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void setupIO(){
#define name "Whisper"
//Phu Trong from Nguyen Tat Thanh High School for gifted student
srand(time(NULL));
cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
//freopen(name".inp", "r", stdin);
//freopen(name".out", "w", stdout);
cout << fixed << setprecision(10);
}
template <class X, class Y>
bool minimize(X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
int numNode, numTime;
int a[MAX];
vector<int> adj[MAX];
int dp[MAX][MAX][2];
void dfs(int u, int p){
for (int i = 1; i <= numTime; ++i) dp[u][i][1] = dp[u][i][0] = a[u];
for (auto&v : adj[u]) if(v ^ p){
dfs(v, u);
REPD(i, numTime + 1) REPD(j, numTime + 1){
if (i >= j + 1){
maximize(dp[u][i][0], dp[u][i - j - 1][1] + max(dp[v][j][0], dp[v][j][1]));
}
if (i >= j + 2){
maximize(dp[u][i][0], dp[v][j][1] + dp[u][i - j - 2][0]);
maximize(dp[u][i][1], dp[v][j][1] + dp[u][i - j - 2][1]);
}
}
}
}
void Whisper(){
cin >> numNode >> numTime;
for (int i = 1; i <= numNode; ++i) cin >> a[i];
for (int i = 1; i < numNode; ++i){
int u, v; cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
dfs(1, 0);
int ans = 0;
for (int i = 1; i <= numTime; ++i){
maximize(ans, dp[1][i][0]);
maximize(ans, dp[1][i][1]);
}
cout << ans;
/*
let dp[u][k][0] is the maximum pepper if we start the path at u and end in u's subtree
let dp[u][k][1] is the maximum pepper if we start the path at u and also end at u
1. dp[u][k][0] = dp[u][k][1] = a[u] with all k <= numTime
2.
maximize(dp[u][i][0], dp[u][i - j - 1][1] + max(dp[v][j][0], dp[v][j][1]))
(we end our path in the subtree v)
3.
maximize(dp[u][i][0], dp[v][j][1] + dp[u][i - j - 2][0])
(we end our path inside another subtree)
maximize(dp[u][i][1], dp[v][j][1] + dp[u][i - j - 2][1])
(we can go through v's subtree)
4. the answer is maximum dp[1][0][i], dp[1][1][i] (0 <= i <= numTime)
*/
}
signed main(){
setupIO();
int Test = 1;
// cin >> Test;
for ( int i = 1 ; i <= Test ; i++ ){
Whisper();
if (i < Test) cout << '\n';
}
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
344 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
2396 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
2392 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
2652 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
2652 KB |
Output is correct |
| 2 |
Correct |
3 ms |
2648 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
2652 KB |
Output is correct |
| 2 |
Correct |
41 ms |
2644 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
70 ms |
2640 KB |
Output is correct |
| 2 |
Correct |
23 ms |
2704 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
25 ms |
2952 KB |
Output is correct |
| 2 |
Correct |
152 ms |
2644 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
134 ms |
3512 KB |
Output is correct |
| 2 |
Correct |
53 ms |
3412 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
290 ms |
4512 KB |
Output is correct |
| 2 |
Correct |
26 ms |
3932 KB |
Output is correct |
