Submission #1111104

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111104		ljtunas	Election Campaign (JOI15_election_campaign)	C++17	100 / 100	167 ms	87116 KiB

election_campaign

// author : anhtun_hi , nqg
#include <bits/stdc++.h>
#define ll long long
#define ii pair<ll, ll>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define reset(h, v)    memset(h, v, sizeof h)
#define Forv(i, a)     for(auto& i : a)
#define For(i, a, b)   for(int i = a; i <= b; ++i)
#define Ford(i, a, b)  for(int i = a; i >= b; --i)
#define c_bit(i)     __builtin_popcountll(i)
#define Bit(mask, i)    ((mask >> i) & 1LL)
#define onbit(mask, i)  ((mask) bitor (1LL << i))
#define offbit(mask, i) ((mask) &~ (1LL << i))
using namespace std;
namespace std {
    template <typename T, int D>
    struct _vector : public vector <_vector <T, D - 1>> {
        static_assert(D >= 1, "Dimension must be positive!");
        template <typename... Args>
        _vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
    };
    template <typename T> struct _vector <T, 1> : public vector <T> {
        _vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
    };
    template <class A, class B> bool minimize(A &a, B b){return a > b ? a = b, true : false;}
    template <class A, class B> bool maximize(A &a, B b){return a < b ? a = b, true : false;}
}
const int dx[] = {0, 0, +1, -1}, dy[] = {-1, +1, 0, 0}, LOG = 20, base = 311, inf = 1e9 + 5;
const int MAXN = 1e6 + 5;
const  ll  mod = 1e9 + 7;
const  ll   oo = 1e18;

//#define int long long

int n, m; vector<int> g[MAXN];

struct Data{ int a, b; ll w; };
vector<Data> qr[MAXN];

int sz[MAXN], dep[MAXN], p[MAXN][22], in[MAXN], en[MAXN];

void dfs(int u, int par) {
    static int timedfs = 0;
    in[u] = ++timedfs;
    p[u][0] = par, sz[u] = 1;
    For(k, 1, 20) p[u][k] = p[p[u][k - 1]][k - 1];
    for(int v : g[u]) {
        if (v == par) continue;
        dep[v] = dep[u] + 1;
        dfs(v, u);
        sz[u] += sz[v];
    }
    en[u] = timedfs;
}

int getlca(int u, int v) {
    if (dep[u] < dep[v]) swap(u, v);
    int len = dep[u] - dep[v];
    For(k, 0, 20) if (Bit(len, k)) u = p[u][k];
    if (u == v) return u;
    Ford(k, 20, 0) if (p[u][k] != p[v][k])
        u = p[u][k], v = p[v][k];
    return p[u][0];
}

ll dp[MAXN];

ll bit[MAXN];
void update(int u, ll val){
    while(u <= 1e5) bit[u] += val, u += u &- u;
}
void update(int l, int r, ll val){
    update(l, val), update(r + 1, - val);
}
ll get(int u){
    ll res = 0;
    while(u) res += bit[u], u -= u &- u;
    return res;
}

void solve(int u, int par){
    ll sum = 0;
    Forv(v, g[u]) if(v ^ par) solve(v, u), sum += dp[v];
    dp[u] = sum;
    for(auto [a, b, c] : qr[u]){
        ll tmp1 = get(in[a]); if(a == u) tmp1 = 0;
        ll tmp2 = get(in[b]); if(b == u) tmp2 = 0;
        maximize(dp[u], c + sum + tmp1 + tmp2);
    }
    update(in[u], en[u], sum - dp[u]);
}

void Solve() {
    cin >> n;
    For(i, 1, n - 1){
        int u, v; cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    dfs(1, 0);
    cin >> m;
    For(i, 1, m){
        int a, b; ll w; cin >> a >> b >> w;
        qr[getlca(a, b)].push_back(Data{a, b, w});
    }
    solve(1, 0);
    ll ans = 0;
    For(i, 1, n) maximize(ans, dp[i]);
    cout << ans << '\n';
}

int32_t main() {
    cin.tie(0) -> sync_with_stdio(0);
    if(fopen("JOI15_election_campaign.inp", "r")) {
        freopen("JOI15_election_campaign.inp", "r", stdin);
        freopen("JOI15_election_campaign.out", "w", stdout);
    }

    int t = 1;
//    cin >> t;

    for (int test = 1; test <= t; test++) {
        Solve();
    }
    return 0;
}

Compilation message (stderr)

election_campaign.cpp: In function 'int32_t main()':
election_campaign.cpp:117:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  117 |         freopen("JOI15_election_campaign.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp:118:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  118 |         freopen("JOI15_election_campaign.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 30 / 30
• Subtask 5: 10 / 10
• Subtask 6: 40 / 40