Submission #373439

#	Time	Username	Problem	Language	Result	Execution time	Memory
373439		Killer2501	Harbingers (CEOI09_harbingers)	C++14	40 / 100	311 ms	60880 KiB

harbingers

#include <bits/stdc++.h>
#define pb push_back
#define vii vector<int>
#define task "fencing"
#define pll pair<ll, ll>
#define pii pair< ll, pair< ll, ll > >
#define fi first
#define se second

using ll = long long;
using ld = long double;
using ull = unsigned long long;
const ll mod = 1e16+7;
using namespace std;
const ll N = 1e5 + 5;
ll tong, m, n, k, ans, t, a[N], b[N], c[N], u, v, cnt, top[N], chain, nchain[N], in[N], sz[N], d[N], par[N];
pll p[N];
//bool check;
string s;
vector<pll> pre, adj[N];
struct line
{
    ll x, y;
    line() {}
    line(ll x, ll y) : x(x), y(y){}

    long double inter(const line& v)const
    {
        return (long double) (v.y-y) * 1.0 / (x-v.x);
    }
    bool cross(const line& p, const line& q) const
    {
        return (long double) (q.y-y) * 1.0 / (x-q.x) - (p.y-y) * 1.0 / (x-p.x) <= 0;
        //return 1.0 *  (q.y - y) / (x - q.x) - 1.0 *  (p.y - y) / (x - p.x) >= 0;
    }

    ll get(ll val)
    {
        return val * x + y;
    }
};
vector<line> st[N*4];
void add(ll id, line d)
{
    while(st[id].size() > 1 && st[id][st[id].size()-2].cross(st[id].back(), d))st[id].pop_back();
    //while(!st[id].empty() && st[id].back().x == d.x)st[id].pop_back();
    st[id].pb(d);
}

ll cal(ll id, ll x)
{
    if(st[id].empty())return mod;
    ll lf = 1, rt = st[id].size()-1, mid;
    while(lf <= rt)
    {
        mid = (lf + rt) / 2;
        if(mid < st[id].size() && st[id][mid-1].get(x) > st[id][mid].get(x))lf = mid + 1;
        else rt = mid - 1;
    }
    return st[id][lf-1].get(x);
}

void update(ll id, ll l, ll r, ll pos, line d)
{
    add(id, d);
    if(l == r)return;
    ll mid = (l + r) /2;
    if(mid >= pos)update(id*2, l, mid, pos ,d);
    else update(id*2+1, mid+1, r, pos ,d);
}
ll get(ll id, ll l, ll r, ll u, ll v, ll x)
{

    if(l > v || u > r || u > v)return mod;
    if(u <= l && r <= v)return cal(id, x);
    ll mid = (l + r ) / 2;
    return min(get(id*2, l, mid, u, v, x), get(id*2+1, mid+1, r, u, v, x));
}
void dfs(ll u, ll p)
{
    sz[u] = 1;
    for(pll v : adj[u])
    {
        if(v.se == p)continue;
        d[v.se] = d[u] + v.fi;
        par[v.se] = u;
        dfs(v.se, u);
        sz[u] += sz[v.se];
    }
}
void getans(ll u, ll xi, ll yi)
{
    ll rt = u;
    //cout << u << '\n';
    ll x = nchain[u], y = nchain[1];
    ll total = mod;
    while(x != y)
    {
        total = min(total, get(1, 1, n, in[top[x]], in[u], xi));
        u = par[top[x]];
        x = nchain[u];
    }
    c[rt] = min(total, get(1, 1, n, 1, in[u], xi))+ d[rt] * xi;
    //cout << c[u] <<" " << yi << '\n';
    c[rt] += yi;
    update(1, 1, n, in[rt], line(-d[rt], c[rt]));
    //cout << c[u] << " " << u << '\n';
}
void hld(ll u, ll pa)
{
    //cout << u <<" "<<k+1<<'\n';
    if(top[chain] == 0)top[chain] = u;
    nchain[u] = chain;
    in[u] = ++k;
    //cout << u <<endl;
    if(u > 1)getans(u, p[u].se, p[u].fi);
    else update(1, 1, n, 1, line(0, 0));
    //cout << u << endl;
    ll big = -1;
    for(pll v : adj[u])
    {
        if(v.se == pa)continue;
        if(big == -1 || sz[v.se] > sz[big])big = v.se;
    }
    if(big != -1)hld(big, u);
    for(pll v : adj[u])
    {
        if(v.se == pa || v.se == big)continue;
        ++chain;
        hld(v.se, u);
    }
}
void sol()
{
    cin >> n;
    for(int i = 1; i < n; i ++)
    {
        ll x, y, w;
        cin >> x >> y >> w;
        adj[x].pb({w, y});
        adj[y].pb({w, x});
    }
    for(int i = 2; i <= n; i ++)cin >> p[i].fi >> p[i].se;
    dfs(1, 0);
    hld(1, 0);
    for(int i = 2; i <= n; i ++)cout << c[i] << ' ';
}
int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if(fopen(task".in", "r"))
    {
        freopen(task".in", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int ntest;
    ntest = 1;
    //cin >> ntest;
    while(ntest -- > 0)
    sol();
}
/*
5
1 3
2 -3
3 -5
0 3
1 10
6
? 1
+ 2 4 10 -10
? 2
? 3
? 4
+ 4 1 9 12
3
1 2
4 6
2 5
4
+ 1 1 -1 2
+ 1 2 -2 3
+ 1 3 1 0
? 1
*/

Compilation message (stderr)

harbingers.cpp: In function 'll cal(ll, ll)':
harbingers.cpp:57:16: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<line>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |         if(mid < st[id].size() && st[id][mid-1].get(x) > st[id][mid].get(x))lf = mid + 1;
      |            ~~~~^~~~~~~~~~~~~~~
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(task".in", "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(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 40 / 100