Submission #885176

#	Time	Username	Problem	Language	Result	Execution time	Memory
885176		nasam	Chase (CEOI17_chase)	C++17	0 / 100	209 ms	265724 KiB

chase

/*************************************
*       author: Pham Huy Khanh       *
*************************************/
#include <bits/stdc++.h>
#define ll long long
#define FOR(i,a,b) for (int i = (a), _b = (b); i <= _b; i++)
#define FOD(i,b,a) for (int i = (b), _a = (a); i >= _a; i--)
#define FORE(i, v) for (__typeof((v).begin()) i = (v).begin(); i != (v).end(); i++)
#define ALL(v) (v).begin(), (v).end()
#define BIT(x, i) (((x) >> (i)) & 1)
#define MASK(i) (1LL << (i))
#define CNTBIT(x) __builtin_popcount(x)
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define left ___left
#define right ___right
#define pii pair<int, int>
#define pll pair<ll, ll>
#define DEBUG(n, a) FOR (i, 1, n) cout << a[i] << ' '; cout << endl;
#define lob lower_bound // >=
#define upb upper_bound // >
#define endl "\n"
#define NAME "main"

using namespace std;

template<class X, class Y> bool maximize(X &x, Y y){ if (x < y){ x = y; return true; } return false; }
template<class X, class Y> bool minimize(X &x, Y y){ if (x > y){ x = y; return true; } return false; }

#define  gogobruhbruh  ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
#define  file(name)  if (fopen (name".inp", "r")) { freopen (name".inp", "r", stdin); freopen (name".out", "w", stdout); }

const int MOD = 998244353;

void add(int &a, int b){ if ((a += b) >= MOD) a -= MOD; }
void sub(int &a, int b){ if ((a -= b) < 0) a += MOD; }
int muti(int a, int b){ return (1LL * a * b) % MOD; }
int Pow(int x, int y){ int res = 1; for (; y; y >>= 1){ if (y & 1) res = muti(res, x); x = muti(x, x); } return res; }

const int MAX = 1e5 + 7;
const int LIM = 1e2 + 7;
const ll INF = 1e18 + 7;

int num, lim;
int val[MAX];
ll dp[MAX][LIM][2], dp2[MAX][LIM];
vector<int> edge[MAX];

void dfs(int u, int pre){
    for (int v : edge[u]){
        if (v == pre)
            continue;
        dfs(v, u);
        FOR (i, 2, lim){
            ll tmp = dp[v][i - 1][0] + dp[u][1][0] - val[v];
            if (tmp > dp[u][i][0])
                dp[u][i][1] = dp[u][i][0],
                dp[u][i][0] = tmp;
            else
                maximize(dp[u][i][1], tmp);
        }
    }
}

void dfs2(int u, int pre){
    for (int v : edge[u]){
        if (v == pre)
            continue;
        FOR (i, 1, lim){
            dp2[v][i + 1] = dp2[u][i] + dp[v][1][0] - val[u];
            ll tmp = dp[v][i - 1][0] + dp[u][1][0] - val[v];
            if (dp[u][i][0] == tmp)
                maximize(dp2[v][i + 1], dp[u][i][1] + dp[v][1][0] - val[u]);
            else
                maximize(dp2[v][i + 1], dp[u][i][0] + dp[v][1][0] - val[u]);
        }
        dfs2(v, u);
    }
}

void solve(){
    dfs(1, -1);
    dfs2(1, -1);
    ll res = 0;
    FOR (u, 1, num)
        FOR (i, 1, lim)
            maximize(res, max(dp[u][i][0], dp2[u][i]));
    cout << res;
}

void read(){
    cin >> num >> lim;
    FOR (i, 1, num)
        cin >> val[i];
    FOR (i, 2, num){
        static int u, v;
        cin >> u >> v;
        edge[u].eb(v);
        edge[v].eb(u);
        dp[u][1][0] += val[v];
        dp[v][1][0] += val[u];
    }
}

int main(){
    gogobruhbruh;
    file("main");
    int test = 1;
    // cin >> test;
    while (test--)
      read(),
      solve();
}

Compilation message (stderr)

chase.cpp: In function 'int main()':
chase.cpp:33:61: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 | #define  file(name)  if (fopen (name".inp", "r")) { freopen (name".inp", "r", stdin); freopen (name".out", "w", stdout); }
      |                                                     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
chase.cpp:109:5: note: in expansion of macro 'file'
  109 |     file("main");
      |     ^~~~
chase.cpp:33:95: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 | #define  file(name)  if (fopen (name".inp", "r")) { freopen (name".inp", "r", stdin); freopen (name".out", "w", stdout); }
      |                                                                                       ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
chase.cpp:109:5: note: in expansion of macro 'file'
  109 |     file("main");
      |     ^~~~

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