Submission #602534

#	Time	Username	Problem	Language	Result	Execution time	Memory
602534		MadokaMagicaFan	Roller Coaster Railroad (IOI16_railroad)	C++14	100 / 100	414 ms	20864 KiB

railroad

#include "bits/stdc++.h"

using namespace std;

using ll = long long;
const ll inf = 1e9+5;
const int md1 = 1e9+7;
const int md2 = 998244353;
using vi = vector<int>;
using ai = array<int, 2>;

#define sz(v)                       ((int)v.size())
#define pb                          push_back

#define pry                         cout << "YES\n"
#define prn                         cout << "NO\n"
#define endl                        '\n'

#define fst                         first
#define scn                         second
/* #define ONPC */

const int N = 2e5+5;
int p[N<<1];

int
lb(int x, vi& v)
{
    int l = 0, r = sz(v);
    int mid;

    while (l < r) {
        mid = (l+r)>>1;
        if (v[mid] > x)
            r = mid;
        else
            l = mid+1;
    }
    return l-1;
}

int
getp(int x)
{
    return p[x] = (x == p[x]) ? x : getp(p[x]);
}

ll
uni(int a, int b)
{
    a = getp(a);
    b = getp(b);

    p[a] = b;
    return (a!=b);
}

ll
plan_roller_coaster(vi s, vi t)
{
    int n = sz(s);
    vi nm;

    for (int i = 0; i < n; ++i) nm.pb(s[i]);
    for (int i = 0; i < n; ++i) nm.pb(t[i]);

    nm.pb(0);
    nm.pb(inf);
    sort(nm.begin(), nm.end());
    nm.resize(distance(nm.begin(), unique(nm.begin(), nm.end())));

    vi qin, qot;

    int pin, pot;
    pin = pot = 0;


    for (int i = 0; i < sz(nm); ++i) p[i] = i;

    for (int i = 0; i < n; ++i) {
        qin.pb(lb(s[i],nm));
        qot.pb(lb(t[i],nm));
        uni(lb(s[i], nm), lb(t[i], nm));
    }
    uni(0, sz(nm)-1);

    /* for (int i = 0; i < 20; ++i) { */
    /*     cout << i << ": " << lb(i, nm) << endl; */
    /* } */

    qot.pb(0);

    sort(qin.begin(), qin.end());
    sort(qot.begin(), qot.end());

    ll ans = 0;

    for (int i = 0; i < sz(nm)-1; ++i) {
        while (pin < sz(qin)) {
            if (qin[pin] > i) break;
            ++pin;
        }
        while (pot < sz(qot)) {
            if (qot[pot] > i) break;
            ++pot;
        }

        if (pot < pin) {
            ans += ((ll) pin-pot) * ((ll) (nm[i+1]-nm[i]));
            uni(i,i+1);
        } else if (pot > pin) {
            uni(i,i+1);
        }
    }

    vector<ai> edg;

    for (int i = 0; i < sz(nm)-1; ++i)
        edg.pb({nm[i+1]-nm[i], i});

    sort(edg.begin(), edg.end());

    for (int i = 0; i < sz(edg); ++i) {
        ans += uni(edg[i][1], edg[i][1]+1) * ((ll)edg[i][0]);
    }

    return ans;
}

#ifdef ONPC
void
solve()
{
    int n;
    cin >> n;

    vi t(n), s(n);

    for (int i = 0; i < n; ++i) cin >> s[i];
    for (int i = 0; i < n; ++i) cin >> t[i];

    cout << plan_roller_coaster(s,t) << endl;
}

int32_t
main(int argc, char **argv)
{
    if (argc >= 2) {
        freopen(argv[1], "r", stdin);
    } else
        ios_base::sync_with_stdio(0);cin.tie(0);
    int t = 1;
    /* cin >> t; */
    while(t--)
        solve();
}
#endif

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 30 / 30
• Subtask 4: 36 / 36