Submission #1158530

#	Time	Username	Problem	Language	Result	Execution time	Memory
1158530		JanPham	Harbingers (CEOI09_harbingers)	C++20	50 / 100	145 ms	109800 KiB

harbingers

#include <bits/stdc++.h>

using namespace std;

#define pb push_back
#define fi first
#define se second
#define TranLeThanhTam "TranLeThanhTam"
#define all(v) v.begin(),v.end()
#define reset(a,i) memset(a,i,sizeof(a))
#define FOR(i,a,b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i,a,b) for (int i = (a), _b = (b); i >= _b; --i)
#define compact(v) sort(all(v)), v.erase(unique(all(v)), end(v))
#define sz(v) (int) v.size()
#define MASK(i) (1 << (i))

typedef long long ll;
typedef long double lb;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;

const int Thanh_Tam = 1e5 + 17;
const int inf = 1e9 + 17;
const long long infll = 1e18 + 17;
const int MOD = 1e9 + 7;
const int Log = 18;
const int dx[4] = {-1, 0, 0, 1};
const int dy[4] = {0, -1, 1, 0};
const int max_block_size = 600;
const ll P = 311;
const int maxA = 1e2 + 17;
const int addi = 1e9;
const char dir[4] = {'W', 'S', 'N', 'E'};
const int Mod[3] = {998244353, MOD, 759186269};

ll mul(ll a, ll b, ll mod);
ll binpow(ll a, ll b, ll mod)
{
    ll res = 1;
    while (b > 0)
    {
        if (b & 1) res = mul(res,a,mod);
        b >>= 1;
        a = mul(a,a,mod);
    }
    return res;
}
ll add(ll a, ll b, ll mod = MOD) { return (a + b) % mod;                 }
ll sub(ll a, ll b, ll mod = MOD) { return (a - b + mod) % mod;          }
ll mul(ll a, ll b, ll mod = MOD) { return ((a % mod) * (b % mod)) % mod; }
ll Div(ll a, ll b, ll mod = MOD) { return mul(a, binpow(b, mod - 2, mod), mod); }

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand_range(ll l, ll r) { return uniform_int_distribution<ll>(l,r)(rng); }

struct Line
{
    int a, b;
    Line() {}
    Line(ll a, ll b) : a(a), b(b) {}
    ll f(ll x) { return a * x + b; }
};

struct Convex_Hull
{
    vector<Line> lines, erased[Thanh_Tam];

    long double intersect(Line C1, Line C2)
    {
        return (1.0 * (C2.b - C1.b)) / (1.0 * (C1.a - C2.a));
    }

    void add(Line L, int u)
    {
        while (sz(lines) > 1)
        {
            if (intersect(L, lines[sz(lines) - 2]) > intersect(L, lines[sz(lines) - 1]))
            {
                erased[u].pb(lines.back());
                lines.pop_back();
            }
            else break;
        }
        lines.push_back(L);
        return;
    }

    ll query(ll x)
    {
        int pos = 0, L = 1, R = sz(lines) - 1;
        while (L <= R)
        {
            int mid = (L + R) >> 1;
            if (lines[mid].f(x) <= lines[mid - 1].f(x)) 
            {
                pos = mid;
                L = mid + 1;
            }
            else R = mid - 1;
        }
        
        return lines[pos].f(x);
    }   

    void rollback(int u)
    {
        lines.pop_back();
        while (!erased[u].empty())
        {
            lines.pb(erased[u].back());
            erased[u].pop_back();
        }
        return;
    }

    void print()
    {
        for (Line T : lines)
            cout << T.a << ' ' << T.b << '\n';
        cout << '\n';
        return;
    }

} CHT;

int n;
vector<pii> adj[Thanh_Tam];
int a[Thanh_Tam], b[Thanh_Tam], dis[Thanh_Tam];
ll ans[Thanh_Tam];

void dfs(int u, int par)
{
    ans[u] = 1LL * a[u] * dis[u] + 1LL * b[u] + CHT.query(a[u]);
    CHT.add(Line(-1LL * dis[u], ans[u]), u);

    for (pii T : adj[u])
    {
        int v = T.fi, w = T.se;
        if (v == par) continue;
        dis[v] = dis[u] + w;
        dfs(v, u);
    }
    CHT.rollback(u);

    return;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    if (fopen(TranLeThanhTam".inp","r"))
    {
        freopen(TranLeThanhTam".inp","r",stdin);
        freopen(TranLeThanhTam".out","w",stdout);
    }

    cin >> n;
    FOR(i,1,n - 1)
    {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].pb({v, w});
        adj[v].pb({u, w});
    }

    FOR(i,2,n) cin >> b[i] >> a[i];

    CHT.add(Line(0, 0), 1);
    for (pii T : adj[1])
    {
        int v = T.fi, w = T.se;
        dis[v] = dis[1] + w;
        dfs(v, 1);
    }
    
    FOR(i, 2, n) cout << ans[i] << ' ';
    return 0;
}

Compilation message (stderr)

harbingers.cpp: In function 'int main()':
harbingers.cpp:156:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  156 |         freopen(TranLeThanhTam".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
harbingers.cpp:157:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  157 |         freopen(TranLeThanhTam".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 50 / 100