Submission #1278734

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278734		Mike_Vu	Two Currencies (JOI23_currencies)	C++17	0 / 100	2 ms	2884 KiB

currencies

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef double dou;
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back
#define BITJ(x, j) (((x)>>(j))&1)
#define MASK(j) (1LL<<(j))
#define ALL(v) v.begin(), v.end()

template<typename T> bool maximize(T &x, const T &y) {
    if (x < y) {x = y; return 1;}
    return 0;
}
template<typename T> bool minimize(T &x, const T &y) {
    if (x > y) {x = y; return 1;}
    return 0;
}

struct BIT{
    int n;
    vector<ll> bit;
    void init(int _n) {
        n = _n;
        bit.assign(n+1, 0);
    }
    void upd(int k, ll x) {
        while (k <= n) {
            bit[k] += x;
            k += k & (-k);
        }
    }
    void update(int l, int r, ll x) {
        upd(l, x);
        upd(r+1, -x);
    }
    ll getsum(int k){
        ll res = 0;
        while (k > 0) {
            res += bit[k];
            k -= k & (-k);
        }
        return res;
    }
};

struct query{
    int u, v, lca;
    ll gold, silver, ans = -1;
    query(int _u, int _v, int _lca, ll _gold, ll _silver) {
        u = _u;
        v = _v;
        lca = _lca;
        gold = _gold;
        silver = _silver;
    }
};

const int maxn = 1e5+5, lg = 17;
int n, m, q;
vector<pii> edges;
vector<int> adj[maxn];
int tin[maxn], tout[maxn], timer = 0, h[maxn], par[maxn][lg];
BIT bit, bitcnt;
vector<pair<ll,int>> updates; //val, node, sort by val
vector<query> qu;

void dfsprep(int u, int p) {
    for (int j = 1; j < lg; j++) {
        if (MASK(j) >= h[u]) continue;
        par[u][j] = par[par[u][j-1]][j-1];
    }
    tin[u] = ++timer;
    for (int v : adj[u]) {
        if (v == p) continue;
        par[v][0] = u;
        h[v] = h[u] + 1;
        dfsprep(v, u);
    }
    tout[u] = timer;
}
bool inside(int u, int v){
    return (tin[u] <= tin[v] && tout[v] <= tout[u]);
}
int findlca(int u, int v) {
    if (inside(u, v)) return v;
    if (inside(v, u)) return u;
    for (int j = lg-1; j >= 0; j--){
        while (MASK(j) < h[u] && !inside(par[u][j], v)) {
            u = par[u][j];
        }
    }
    return par[u][0];
}

void prlbs() {
    vector<int> bleft, bright, bmid, id;
    //update val, update 1
    bleft.assign(q, 0);
    bright.assign(q, m);
    bmid.assign(q, m/2);
    while (true) {
        bool can = 0;
        id.clear();
        for (int i = 0; i < q; i++) {
            if (bleft[i] <= bright[i]) {
                can = 1;
                bmid[i] = (bleft[i]+bright[i])>>1;
                id.pb(i);
            }
        }
        if (!can) break;
        sort(ALL(id), [&](int a, int b){return bmid[a] < bmid[b];});
        int j = 0;
        bit.init(n);
        bitcnt.init(n);
        for (int i = 0; i < m; i++) {
            int u = updates[i].se;
            bitcnt.update(tin[u], tout[u], 1);
        }
        for (int i : id){
            while (j < bmid[i]) {
                int u = updates[j].se;
                bit.update(tin[u], tout[u], updates[j].fi);
                bitcnt.update(tin[u], tout[u], -1);
                ++j;
            }
//            cout << "mid " << bmid[i] << "\n";
            ll sum = bit.getsum(tin[qu[i].u])+bit.getsum(tin[qu[i].v]);
            sum -= bit.getsum(tin[qu[i].lca])*2;
//            cout << sum << "\n";
            if (sum > qu[i].silver) {
                //case too much
                bright[i] = bmid[i]-1;
                continue;
            }
            int cnt = bitcnt.getsum(tin[qu[i].u])+bitcnt.getsum(tin[qu[i].v]);
            sum -= bitcnt.getsum(tin[qu[i].lca])*2;
//            cout << cnt << "\n";
            if (cnt > qu[i].gold){
                //case too low
                bleft[i] = bmid[i]+1;
                continue;
            }
            //case ok, try to find if there is any optimal solution
            maximize(qu[i].ans, qu[i].gold-cnt);
            bleft[i] = bmid[i]+1;
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
//    #define name "task"
//    if (fopen(name".inp", "r")) {
//        freopen(name".inp", "r", stdin);
//        freopen(name".out", "w", stdout);
//    }
    //input
    cin >> n >> m >> q;
    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        edges.pb({u, v});
        adj[u].pb(v);
        adj[v].pb(u);
    }
    //dfs tin tout
    h[1] = 1;
    dfsprep(1, -1);
    //take updates, rephrase, sort
    for (int i= 1; i <= m; i++) {
        int p;
        ll x;
        cin >> p >> x;
        --p;
        int u = tin[edges[p].fi] > tin[edges[p].se] ? edges[p].fi : edges[p].se;
//        cout << p << ' ' << u << "\n";
        updates.pb(make_pair(x, u));
    }
    sort(ALL(updates));
    //take queries
    for (int i= 1; i <= q; i++) {
        int u, v;
        ll gold, silver;
        cin >> u >> v >> gold >> silver;
//        cout << u << ' ' << v << ' ' << findlca(u, v) << "\n";
        qu.pb(query(u, v, findlca(u, v), gold, silver));
    }
    //parallel binsearch
    prlbs();
    //output
    for (int i = 0; i < q; i++) {
        cout << qu[i].ans << "\n";
    }
}
/*
5 4 1
1 2
1 3
2 4
2 5

2 9
2 4
3 5
4 7
3 4 2 11

5 4 3
1 2
1 3
2 4
2 5
2 9
2 4
3 5
4 7
3 4 2 11
5 3 4 5
2 3 1 1
*/

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