Submission #319588

#	Time	Username	Problem	Language	Result	Execution time	Memory
319588		parsabahrami	Chase (CEOI17_chase)	C++17	100 / 100	620 ms	488804 KiB

chase

//! The Leader Of Retards Bemola
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<ll, ll> pll;
 
#define sz(x)                       (ll) x.size()
#define all(x)                      (x).begin(),(x).end()
#define F                           first
#define S                           second

ll Pow(ll a, ll b, ll md, ll ans = 1) {
    for (; b; b >>= 1, a = a * a % md)
        if (b & 1)
            ans = ans * a % md;
    return ans % md;
}
const ll MAXN = 1e5 + 10;
const ll MAXK = 101;
const ll INF  = 8e18;
const ll MOD  = 1e9 + 7;
ll P[MAXN], M[MAXN], n, ans = 0, k; 
vector<ll> adj[MAXN]; pll dp[MAXN][MAXK], pd[MAXN][MAXK], idp[MAXN][MAXK], ipd[MAXN][MAXK];

void merge(ll v, ll u, ll x) {
	if (dp[v][x].S < max(dp[u][x].F, dp[u][x - 1].F + M[u] - P[v])) dp[v][x].S = max(dp[u][x].F, dp[u][x - 1].F + M[u] - P[v]), idp[v][x].S = u;
	if (dp[v][x].F < dp[v][x].S) swap(dp[v][x].F, dp[v][x].S), swap(idp[v][x].F, idp[v][x].S);
	if (pd[v][x].S < max(pd[u][x].F, pd[u][x - 1].F + M[v] - P[u])) pd[v][x].S = max(pd[u][x].F, pd[u][x - 1].F + M[v] - P[u]), ipd[v][x].S = u;
	if (pd[v][x].F < pd[v][x].S) swap(pd[v][x].F, pd[v][x].S), swap(ipd[v][x].F, ipd[v][x].S);
}

void DFS(ll v, ll p = -1) {
	pd[v][1].F = M[v]; ipd[v][1].F = v;
	for (ll u : adj[v]) {
		if (u != p) {
			DFS(u, v);
			for (ll i = 1; i < MAXK; i++) {
				merge(v, u, i);
			}
		}
	}
	for (ll i = 0; i <= k; i++) {
		if (ipd[v][i].F == idp[v][k - i].F) ans = max({ans, pd[v][i].F + dp[v][k - i].S, pd[v][i].S + dp[v][k - i].F});
		else ans = max(ans, pd[v][i].F + dp[v][k - i].F);
	}
}

int main() {
	scanf("%lld%lld", &n, &k);
	for (ll i = 1; i <= n; i++) scanf("%lld", &P[i]);
	for (ll i = 1; i < n; i++) {
		ll u, v; scanf("%lld%lld", &u, &v);
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	for (ll i = 1; i <= n; i++) {
		for (ll u : adj[i]) M[i] += P[u];
	}
	DFS(1);
	printf("%lld\n", ans);
    return 0;
}

Compilation message (stderr)

chase.cpp: In function 'int main()':
chase.cpp:51:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   51 |  scanf("%lld%lld", &n, &k);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~
chase.cpp:52:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   52 |  for (ll i = 1; i <= n; i++) scanf("%lld", &P[i]);
      |                              ~~~~~^~~~~~~~~~~~~~~
chase.cpp:54:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   54 |   ll u, v; scanf("%lld%lld", &u, &v);
      |            ~~~~~^~~~~~~~~~~~~~~~~~~~

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