Submission #921343

# Submission time Handle Problem Language Result Execution time Memory
921343 2024-02-03T17:56:55 Z danikoynov Shortcut (IOI16_shortcut) C++14
Compilation error
0 ms 0 KB
#include "shortcut.h"
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

const ll maxn = 3010;
const ll inf = 1e18;
ll n;
ll cp[maxn], cs[maxn], pref[maxn], bef[maxn], aft[maxn];
ll l[maxn], d[maxn], c;

ll dist[maxn];
struct edge
{
    ll to;
    ll w;

    edge(ll _to = 0, ll _w = 0)
    {
        to = _to;
        w = _w;
    }

    bool operator < (const edge &e) const
    {
        return w > e.w;
    }
};

ll used[maxn];

ll get_dist(ll l, ll r)
{
    if (l > r)
        swap(l, r);
    return pref[r - 1] - pref[l - 1];
}

const ll maxlog = 21;

struct sparse_table
{
    ll dp[maxlog][maxn];
    ll lg[maxn];

    void build(vector < ll > values)
    {
        ll len = values.size();
        for (ll i = 1; i <= len; i ++)
        {
            lg[i] = lg[i / 2]  + 1;
            dp[0][i] = values[i - 1];
        }

        for (ll j = 1; j < lg[len]; j ++)
        {
            for (ll i = 1; i <= len - (1 << j) + 1; i ++)
            {
                dp[j][i] = dp[j - 1][i + (1 << (j - 1))];
                if (dp[j - 1][i] > dp[j][i])
                    dp[j][i] = dp[j - 1][i];
            }
        }
    }

    ll query(ll l, ll r)
    {
        if (l > r)
            return 0;
        ll mlog = lg[r - l + 1] - 1;
        ll ans = dp[mlog][r - (1 << mlog) + 1];
        if (dp[mlog][l] > ans)
            ans = dp[mlog][l];
        return ans;
    }
};


struct poll
{
    ll x, y;

    poll(ll _x = 0, ll _y = 0)
    {
        x = _x;
        y = _y;
    }
};
struct rectangle
{
    poll centre;
    ll diagonal;

    rectangle(poll _centre = poll(), ll _diagonal = 0)
    {
        centre = _centre;
        diagonal = _diagonal;
    }
};

ll p[maxn];


struct event
{
    ll type;
};
bool check(ll x)
{


    vector < rectangle > con;
    for (ll i = 1; i <= n; i ++)
    {
        for (ll j = i + 1; j <= n; j ++)
        {
            ll path = get_dist(i, j) + d[i] + d[j];
            if (path <= x)
                continue;
            //cout << "condition " << i << " " << j << endl;
            //cout << p[i] << " " << p[j] << " " << x - d[i] - d[j] << endl;
            /// |x[i] - x[l]| + |x[j] - x[r]| + d[i] + d[j] + c<= k
            /// |x[l] - x[i]| + |x[r] - x[j]| <= k - d[i] - d[j] - c
            con.push_back(rectangle(poll(p[i], p[j]), x - d[i] - d[j] - c));
        }
    }

    if (con.empty())
        return true;

        ///pair < ll, ll > ans;
    for (ll i = 0; i < con.size(); i ++)
    {
        ll top = inf;
        ll bot = -inf;
        for (ll j = 0; j <= i; j ++)
        {
            top = min(top, con[j].centre.y + con[j].diagonal - (con[i].centre.x - con[j].centre.x));
            bot = max(bot, con[j].centre.y - con[j].diagonal + (con[i].centre.x - con[j].centre.x));
        }

        for (ll j = i + 1; j < con.size(); j ++)
        {
            top = min(top, con[j].centre.y + con[j].diagonal - (con[j].centre.x - con[i].centre.x));
            bot = max(bot, con[j].centre.y - con[j].diagonal + (con[j].centre.x - con[i].centre.x));
        }

        for (ll f = 1; f <= n; f ++)
        {
            if (p[f] >= bot && p[f] <= top)
            {
                bool tf = true;
                for (rectangle rec : con)
                {
                    ll val = abs(con[i].centre.x - rec.centre.x) + abs(p[f] - rec.centre.y);
                    if (val > rec.diagonal)
                    {
                        //cout << "fuck " << l << " " << r << endl;
                        //cout << "rectangle " << rec.centre.x << " " << rec.centre.y << " " << rec.diagonal << endl;
                        tf = false;
                        break;
                    }
                }
                if (tf == false)
                {
                    assert(false);
                }
                return true;
            }
        }
    }

    return false;
    for (ll l = 1; l <= n; l ++)
        for (ll r = l; r <= n; r ++)
        {
            bool tf = true;
            for (rectangle rec : con)
            {
                ll val = abs(p[l] - rec.centre.x) + abs(p[r] - rec.centre.y);
                if (val > rec.diagonal)
                {
                    //cout << "fuck " << l << " " << r << endl;
                    //cout << "rectangle " << rec.centre.x << " " << rec.centre.y << " " << rec.diagonal << endl;
                    tf = false;
                    break;
                }
            }
            if (tf)
            {
                //cout << "works " << l << " " << r << endl;
                return true;
            }
        }

    return false;


}


ll find_shortcut(ll N, vector<ll> L, vector<ll> D, ll C)
{
    n = N;
    c = C;
    for (ll i = 0; i < n - 1; i ++)
        l[i + 1] = L[i];
    for (ll i = 0; i < n; i ++)
        d[i + 1] = D[i];

    p[1] = 0;
    for (ll i = 2; i <= n; i ++)
    {
        p[i] = p[i - 1] + l[i - 1];
    }

    for (ll i = 1; i <= n; i ++)
    {
        pref[i] = pref[i - 1] + l[i];
    }

    for (ll i = 1; i <= n; i ++)
    {
        cp[i] = cp[i - 1] + l[i - 1];
        cp[i] = max(cp[i], d[i]);
        bef[i] = bef[i - 1];
        for (ll j = 1; j < i; j ++)
        {
            bef[i] = max(bef[i], get_dist(i, j) + d[i] + d[j]);
        }
    }

    for (ll i = n; i > 0; i --)
    {
        cs[i] = cs[i + 1] + l[i];
        cs[i] = max(cs[i], d[i]);
        aft[i] = aft[i + 1];
        for (ll j = i + 1; j <= n; j ++)
        {
            aft[i] = max(aft[i], get_dist(i, j) + d[i] + d[j]);
        }
    }




    ll lf = 0, rf = inf;
    while(lf <= rf)
    {
        ll mf = (lf + rf) / 2;
        if (check(mf))
            rf = mf - 1;
        else
            lf = mf + 1;
    }


    return lf;
}

Compilation message

shortcut.cpp: In function 'bool check(ll)':
shortcut.cpp:133:22: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<rectangle>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  133 |     for (ll i = 0; i < con.size(); i ++)
      |                    ~~^~~~~~~~~~~~
shortcut.cpp:143:30: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<rectangle>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  143 |         for (ll j = i + 1; j < con.size(); j ++)
      |                            ~~^~~~~~~~~~~~
/usr/bin/ld: /tmp/ccfdyvyP.o: in function `main':
grader.cpp:(.text.startup+0x124): undefined reference to `find_shortcut(int, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, int)'
collect2: error: ld returned 1 exit status