Submission #506374

#	Time	Username	Problem	Language	Result	Execution time	Memory
506374		mewnian	Palembang Bridges (APIO15_bridge)	C++14	41 / 100	2066 ms	16324 KiB

bridge

//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("avx,avx2,fma")

#include <bits/stdc++.h>
#define sze(x) (ll) x.size()
#define idx(x, a) get<x>(a)
#define LID(x) (x << 1LL)
#define RID(x) (x << 1LL) + 1LL
#define ID(x) (x + MAXN)
#define CONV(x) (x - MAXN)
#define countbit(x) __builtin_popcountll(x)
#define pb push_back
#define mp make_pair
#define fi first
#define se second

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pi;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

ll rand(ll l, ll r)
{
    return uniform_int_distribution<ll>(l, r)(rng);
}

inline ll lcm(ll u, ll v)
{
    return u * v / __gcd(u, v);
}

const ll MAXN = 2e5 + 3;
const ll INF = 1e18;

pi a[MAXN];
ll b[MAXN];
ll k, n, m, res = 0;

ll solve(ll u, ll v)
{
    ll rt = 0;
    for (ll i = 1; i <= n; ++i)
    {
        ll mn = min(abs(a[i].fi - u) + abs(a[i].se - u) + 1, abs(a[i].fi - v) + abs(a[i].se - v) + 1);
        rt += mn;
    }
    return rt;
}

ll comp(ll x, ll y)
{
    return (x > y ? 1 : (x < y ? -1 : 0));
}

void solve1()
{
    ll x = b[m / 2];
    for (ll i = 1; i <= n; ++i)
    {
        ll rt = abs(a[i].fi - x) + abs(a[i].se - x) + 1;
        res += rt;
    }
    cout << res;
}

void solve2()
{
    ll rt = INF;
    ll l = 1, r = 2, curans = INF;
    vector<ll> cl(m + 2);
    vector<ll> cr(m + 2);
    while (r <= m)
    {
        ll tans = solve(b[l], b[r]);
        if (tans <= curans)
        {
            curans = tans;
            ++r;
        }
        else
        {
            cl[l] = r - 1;
            ++l;
            if (l < r - 1) curans = solve(b[l], b[r - 1]);
            else curans = INF;
        }
    }
    for (ll i = 1; i < m; ++i) if (cl[i] == 0) cl[i] = m;
    for (ll i = 1; i < m; ++i) rt = min(rt, solve(b[i], b[cl[i]]));
//    ll check = INF;
//    for (ll l = 1; l <= m; ++l)
//    {
//        ll pre = INF, idx = 0;
//        for (ll r = l + 1; r <= m; ++r)
//        {
//            ll tans = solve(b[l], b[r]);
////            if (pre < tans) break;
//            if (tans <= pre)
//            {
//                pre = tans;
//                idx = r;
//            }
//        }
//        cr[l] = idx;
//        check = min(check, pre);
//    }
//    for (ll i = 1; i <= m; ++i) cerr << cl[i] << " "; cerr << endl;
//    for (ll i = 1; i <= m; ++i) cerr << cr[i] << " "; cerr << endl;
//    cerr << rt << " " << check << endl;
//    assert(rt == check);
    if (rt != INF) res += rt;
    cout << res;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    #ifdef OFFLINE
    freopen("input.inp", "r", stdin);
    #endif
    ll _;
    cin >> k >> _;
    n = 0, m = 0;
    ll mn = INF, mx = -INF;
    set<ll> s;
    for (ll i = 1; i <= _; ++i)
    {
        char c1, c2; ll p1, p2; cin >> c1 >> p1 >> c2 >> p2;
//        c1 = 'A', c2 = 'B';
//        p1 = rand(1, _), p2 = rand(1, _);
//        cerr << c1 << " " << p1 << " " << c2 << " " << p2 << endl;
        if (c1 == c2) res += abs(p1 - p2);
        else
        {
            s.insert(p1); s.insert(p2);
            a[++n] = {p1, p2};
        }
    }
    for (auto& v : s) b[++m] = v;
    b[m + 1] = 1e12;
    if (k == 1) solve1();
    else solve2();
}

Compilation message (stderr)

bridge.cpp: In function 'int main()':
bridge.cpp:130:8: warning: unused variable 'mn' [-Wunused-variable]
  130 |     ll mn = INF, mx = -INF;
      |        ^~
bridge.cpp:130:18: warning: unused variable 'mx' [-Wunused-variable]
  130 |     ll mn = INF, mx = -INF;
      |                  ^~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 14
• Subtask 3: 9 / 9
• Subtask 4: 32 / 32
• Subtask 5: 0 / 37