Submission #792546

#	Time	Username	Problem	Language	Result	Execution time	Memory
792546		vjudge1	Two Currencies (JOI23_currencies)	C++14	38 / 100	749 ms	93676 KiB

currencies

#include<bits/stdc++.h>
#define ll long long
#define fi first
#define se second
using namespace std ;
const ll N = 1e5, NS = 2e3 ;
bool flag1 ;
ll n, m, q, ans, p[N + 1], c[N + 1], ind[N + 1], pw[2 * N + 1], dist1[N + 1], dist[N + 1] ;
pair<ll, ll> mn[2 * N + 1][20] ;
map<pair<ll, ll>, vector<ll>> mp ;
vector<ll> now, tree[NS + 1] ;
vector<pair<pair<ll, ll>, ll>> road ;
vector<pair<ll, ll>> v1, v[N + 1] ;
void dfs_perebor(ll city, ll last, ll t, ll x, ll y)
{
    if(city == t)
    {
        ll kol = 0 ;
        sort(now.begin(), now.end()) ;
        for(ll i : now)
        {
            if(y >= i)
                y -= i, kol++ ;
            else
                break ;
        }
        ans = max(-1ll, x - ((ll)now.size() - kol)) ;
        return ;
    }
    for(ll i : tree[city])
    {
        if(i == last)
            continue ;
        for(ll j : mp[{city, i}])
            now.push_back(j) ;
        dfs_perebor(i, city, t, x, y) ;
        for(ll j : mp[{city, i}])
            now.pop_back() ;
    }
}
void dfs_for_st(ll city, ll last)
{
    ind[city] = v1.size() ;
    v1.push_back({dist1[city], city}) ;
    for(auto i : v[city])
    {
        if(i.fi == last)
            continue ;
        dist[i.fi] = dist[city] + i.se ;
        dist1[i.fi] = dist1[city] + 1 ;
        dfs_for_st(i.fi, city) ;
        v1.push_back({dist1[city], city}) ;
    }
}
void build_sparce_table()
{
    for(ll i = 2 ; i <= (ll)v1.size() ; i++)
        pw[i] = pw[i / 2] + 1 ;
    for(ll i = 0 ; i < (ll)v1.size() ; i++)
        mn[i][0] = v1[i] ;
    for(ll i = 1 ; i < 20 ; i++)
        for(ll j = 0 ; j <= (ll)v1.size() - (1 << i) ; j++)
            mn[j][i] = min(mn[j][i - 1], mn[j + (1 << (i - 1))][i - 1]) ;
}
ll get_lca(ll a, ll b)
{
    a = ind[a] ;
    b = ind[b] ;
    if(a > b)swap(a, b) ;
    ll num = pw[b - a + 1] ;
    return min(mn[a][num], mn[b - (1 << num) + 1][num]).se ;
}
ll get_dist(ll a, ll b)
{
    ll lc = get_lca(a, b) ;
    return dist[a] + dist[b] - dist[lc] * 2ll ;
}
signed main()
{
    ios_base::sync_with_stdio( 0 ) ;
    cin.tie( 0 ) ;
    cout.tie( 0 ) ;
    cin >> n >> m >> q ;
    for(ll i = 1 ; i < n ; i++)
    {
        ll a, b ;
        cin >> a >> b ;
        if(n <= 2000 && m <= 2000 && q <= 2000)
        {
            tree[a].push_back(b) ;
            tree[b].push_back(a) ;
        }
        road.push_back({{a, b}, 0}) ;
    }
    for(ll i = 1 ; i <= m ; i++)
    {
        cin >> p[i] >> c[i] ;
        if(n <= 2000 && m <= 2000 && q <= 2000)
        {
            pair<ll, ll> pr = road[p[i] - 1].fi ;
            mp[pr].push_back(c[i]) ;
            mp[{pr.se, pr.fi}].push_back(c[i]) ;
        }
        if(c[i] != c[1])
            flag1 = 1 ;
    }
    if(!flag1)
    {
        for(ll i = 1 ; i <= m ; i++)
            road[p[i] - 1].se += c[i] ;
        for(auto i : road)
            v[i.fi.fi].push_back({i.fi.se, i.se}), v[i.fi.se].push_back({i.fi.fi, i.se}) ;
        dfs_for_st(1, 0) ;
        build_sparce_table() ;
        while(q--)
        {
            ll s, t, x, y ;
            cin >> s >> t >> x >> y ;
            ll ds = get_dist(s, t) ;
            ds /= c[1] ;
            y /= c[1] ;
            ds -= min(ds, y) ;
            cout << max(-1ll, x - ds) << '\n' ;
        }
        return 0 ;
    }
    if(n <= 2000 && m <= 2000 && q <= 2000)
    {
        while(q--)
        {
            ll s, t, x, y ;
            cin >> s >> t >> x >> y ;
            dfs_perebor(s, 0, t, x, y) ;
            cout << ans << '\n' ;
        }
        return 0 ;
    }
    return 0 ;
}

Compilation message (stderr)

currencies.cpp: In function 'void dfs_perebor(long long int, long long int, long long int, long long int, long long int)':
currencies.cpp:37:16: warning: unused variable 'j' [-Wunused-variable]
   37 |         for(ll j : mp[{city, i}])
      |                ^

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