Submission #1196786

#	Time	Username	Problem	Language	Result	Execution time	Memory
1196786		Ghulam_Junaid	Harbingers (CEOI09_harbingers)	C++20	70 / 100	269 ms	131072 KiB

harbingers

#include <bits/stdc++.h>
using namespace std;

#define F first
#define S second

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

const int N = 1e5 + 10;
int n, sz;
int s[N], req[N], d[N];
ll dp[N];
vector<pii> g[N];
vector<pll> del[N];
pll hull[N];

bool cmp(pll x, pll y){
    if ((x.F / x.S) != (y.F / y.S))
        return (x.F / x.S) > (y.F / y.S);
    x.F %= x.S;
    y.F %= y.S;
    return (x.F * y.S) > (y.F * x.S);
}

bool useful(pll &x, pll &y, pll &z){
    return cmp({x.S - y.S, y.F - x.F}, {y.S - z.S, z.F - y.F});
}

void insert(int v, pll L){
    while (sz > 1 and !useful(hull[sz - 2], hull[sz - 1], L)){
        del[v].push_back(hull[sz - 1]);
        sz--;
    }
    hull[sz++] = L;
}

ll f(pll &L, int &x){
    return L.F * x + L.S;
}

ll ans, ans1, ans2;
int lo, hi, mid;
ll query(int x){
    ans = f(hull[0], x);
    lo = 0, hi = sz;
    while (hi - lo > 1){
        mid = (lo + hi) / 2;
        ans1 = f(hull[mid - 1], x);
        ans2 = f(hull[mid], x);

        if (ans1 < ans2){
            ans = ans1;
            hi = mid;
        }
        else{
            ans = ans2;
            lo = mid;
        }
    }
    return ans;
}

void dfs(int v, int p = -1){
    for (auto &[w, u] : g[v]){
        if (u == p) continue;
        d[u] = d[v] + w;
        
        dp[u] = query(-s[u]) + 1ll * s[u] * d[u] + req[u];
        insert(u, {d[u], dp[u]});

        dfs(u, v);
    }
    sz--;
    while (del[v].size())
        hull[sz++] = del[v].back(), del[v].pop_back();
    del[v].resize(0);
}

int main(){
    cin >> n;
    for (int i = 0; i < n - 1; i ++){
        int u, v, w;
        cin >> u >> v >> w;
        g[u].push_back({w, v});
        g[v].push_back({w, u});
    }
    for (int i = 2; i <= n; i ++)
        cin >> req[i] >> s[i];

    insert(1, {0, 0});
    dfs(1);
    for (int i = 2; i <= n; i ++)
        cout << dp[i] << " ";
    cout << endl;
}

• Subtask 1: 70 / 100