Submission #749385

#	Time	Username	Problem	Language	Result	Execution time	Memory
749385		Ozy	Two Currencies (JOI23_currencies)	C++17	0 / 100	2 ms	2812 KiB

currencies

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define debug(a) cout << #a << " = " << a << endl
#define debugsl(a) cout << #a << " = " << a << ", "
#define rep(i,a,b) for(int i = (a); i <= (b); i++)
#define repa(i,a,b) for(int i = (a); i >= (b); i--)
#define pll pair<lli,lli>

#define MAX 100000
//para los hijos
#define des first
#define w second

lli n,m,q,silver,x,y,k,cont,a,b;
pair<pll, lli> aristas[MAX+2];
vector<pll> hijos[MAX+2];
lli dis[MAX+2],anc[22][MAX+2];
pll rango[MAX+2];

void dfs(lli pos,lli padre, lli s) {

    dis[pos] = dis[padre]+s;

    anc[0][pos] = padre;
    lli x = padre;
    rep(i,1,20) {
        anc[i][pos] = anc[i-1][x];
        x = anc[i][pos];
    }

    rango[pos].first = cont++;
    for(auto h : hijos[pos]) {
        if (h.des == padre) continue;
        dfs(h.des,pos,h.w);
    }
    rango[pos].second = cont++;

}

lli lca(lli a, lli b) {

    if (rango[a].first > rango[b].first) swap(a,b);

    if (rango[a].second > rango[b].second) return a;

    lli x;
    repa(i,20,0) {
        x = anc[i][a];
        if (x == 0) continue;

        if (rango[x].first < rango[a].first && rango[x].second > rango[b].second) continue;
        a = anc[i][a];
    }
    a = anc[0][a];
    return a;
}

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

    cin >> n >> m >> q;
    rep(i,1,n-1) {
        cin >> a >> b;
        aristas[i] = {{a,b},0};
    }
    rep(i,1,m) {
        cin >> a >> b;
        silver = b;
        aristas[a].second = 1;
    }
    rep(i,1,n-1) {
        hijos[aristas[i].first.first].push_back({aristas[i].first.second,aristas[i].second});
        hijos[aristas[i].first.second].push_back({aristas[i].first.first,aristas[i].second});
    }

    //solcuion
    cont = 1;
    dfs(1,0,0);

    rep(i,1,q) {
        cin >> a >> b >> x >> y;
        k = lca(a,b);

        k = dis[a]+ dis[b] - 2*dis[k];
        y /= silver;
        k -= y;

        if (k <= 0) cout << x << "\n";
        else if (x >= k) cout << (x-k) << "\n";
        else cout << -1 << "\n";
    }

    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 28
• Subtask 3: 0 / 30
• Subtask 4: 0 / 32