Submission #122304

#	Time	Username	Problem	Language	Result	Execution time	Memory
122304		BThero	Chase (CEOI17_chase)	C++17	50 / 100	2324 ms	250196 KiB

chase

// Why am I so dumb? :c
// chrono::system_clock::now().time_since_epoch().count()

//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

#define pb push_back
#define mp make_pair

#define all(x) (x).begin(), (x).end()

#define fi first
#define se second

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;   
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int MAXN = (int)1e5 + 5;
const ll INF = (ll)1e18;

vector<int> adj[MAXN];

ll dp[3][105][MAXN];

ll neigh[MAXN];

int arr[MAXN];

int n, k;

ll ans;

void dfs(int v, int pr = -1) {    
    for (int i = 0; i <= k; ++i) {
        ans = max(ans, dp[0][i][v]);
        ans = max(ans, dp[1][i][v]);
        ans = max(ans, dp[2][i][v]);
    } 

    for (int to : adj[v]) {
        if (to != pr) {
            for (int i = 0; i <= k; ++i) {
                dp[0][i][to] = max(dp[0][i][v], dp[2][i][v]);
                dp[1][i + 1][to] = max(dp[1][i + 1][to], max(dp[1][i][v], dp[2][i][v]) + neigh[to] - arr[v]);
                dp[1][i + 1][to] = max(dp[1][i + 1][to], dp[0][i][v] + neigh[to] - arr[v]);
                dp[2][i][to] = dp[1][i][v];
            }

            dfs(to, v);
        }
    }
}

void solve() {
    scanf("%d %d", &n, &k);

    for (int i = 1; i <= n; ++i) {
        scanf("%d", &arr[i]);
    }

    for (int i = 1; i < n; ++i) {
        int u, v;
        scanf("%d %d", &u, &v);
        neigh[u] += arr[v];
        neigh[v] += arr[u];
        adj[u].pb(v);
        adj[v].pb(u);
    }    

    vector<int> vs;

    if (n <= 100) {
        for (int i = 1; i <= n; ++i) {
            vs.pb(i);
        }
    }
    else {
        vs.pb(1);
    }

    for (int v : vs) {
        for (int i = 1; i <= n; ++i) {
            for (int j = 0; j <= k; ++j) {
                dp[0][j][i] = -INF;
                dp[1][j][i] = -INF;
                dp[2][j][i] = -INF;
            }
        }

        dp[0][0][v] = 0;
        dp[1][1][v] = neigh[v];
        dfs(v, -1);
    }

    printf("%lld\n", ans);
}

int main() {
    int tt = 1;

    while (tt--) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

chase.cpp: In function 'void solve()':
chase.cpp:62:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &k);
     ~~~~~^~~~~~~~~~~~~~~~~
chase.cpp:65:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &arr[i]);
         ~~~~~^~~~~~~~~~~~~~~
chase.cpp:70:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &u, &v);
         ~~~~~^~~~~~~~~~~~~~~~~

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