제출 #239438

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
239438		nicolaalexandra	Aliens (IOI16_aliens)	C++14	60 / 100	2073 ms	10052 KiB

aliens

#include <bits/stdc++.h>
#include "aliens.h"
#define DIMN 100010
#define DIMM 1000010
#define INF 2000000000000000000LL
using namespace std;

int n,k,m,i,j,x,y;
vector <int> r,c;

long long dp[DIMN],cnt[DIMN];
pair <int, int> v[DIMN];

struct dreapta{
    long long a,b,cnt;
};

struct cmp{
    bool operator()(dreapta x, dreapta y){
        if (x.a == y.a)
            return x.b < y.b;
        return x.a > y.a; /// descrescator dupa panta
    }
};
set <dreapta,cmp> s;


long long f (long long a, long long b, int x){
    if (a == INF && b == INF)
        return INF;
    return a*x + b;
}

bool intersectie (pair<long long,long long> c, pair<long long,long long> b, pair<long long,long long> a){
    return (a.second-c.second)*(b.first-a.first) < (a.second-b.second)*(c.first-a.first);
}
void add (long long a, long long b, long long cnt){
    set <dreapta> ::iterator it = s.find({a,b,cnt});
    if (it != s.end() && it->a == a && it->b == b) /// nu are sens sa mai adaug dreapta
        return;
    /// in set le am sortate dupa panta
    /// acum trebuie sa vad ce drepte scoate si din stanga si din dreapta
    it = s.lower_bound({a,b,cnt});
    if (it != s.begin()){
        it--; /// primul mai mic
        int ok = 1;
        do{
            if (it != s.begin()){ /// mai am drepte in stanga
                set <dreapta> :: iterator it2 = it;
                it2--;
                if (intersectie(make_pair(a,b),make_pair(it->a,it->b),make_pair(it2->a,it2->b))){
                    s.erase(it);
                    it = it2;
                } else ok = 0; /// nu mai scoate nimic
            } else ok = 0; /// nu mai am drepte
        } while (ok);
    }

    it = s.lower_bound({a,b,cnt});
    if (it != s.begin() && it != s.end()){
        set <dreapta> :: iterator it2 = it;
        it2--;
        if (intersectie (make_pair(it->a,it->b),make_pair(a,b),make_pair(it2->a,it2->b)) == 0){
            s.insert({a,b,cnt});
            return;
        }}
    else s.insert({a,b,cnt});
}

pair<long long, long long> query (long long x){
    /// daca am query uri crescatoare pot sa sterg din fata
    set <dreapta> :: iterator it = s.begin();
    while (it != s.end()){
        set <dreapta> :: iterator it2 = it;
        it2++;
        if (it2 == s.end())
            break;
        if (it->a*x+it->b > it2->a*x+it2->b){
            /// il sterg pe it
            s.erase(it);
            it = it2;
        } else break;
    }
    return make_pair(it->a * x + it->b,it->cnt);
}

long long patrat (long long x){
    return x*x;
}
long long modul (long long x){
    return max (x,-x);
}
inline int cmp (pair<int,int> a, pair<int,int> b){
    if (a.first == b.first)
        return a.second > b.second;
    return a.first < b.first;
}

void solve (long long lambda){

    /// dp[i] - costul mimim daca am primele i puncte
    /// cnt[i] - de cate subsecvente am nevoie

    //for (int i=0;i<=n;++i)
      //  dp[i] = cnt[i] = 0;
    //for (int i=1;i<=4*m;++i)
      //  aint[i] = {INF,INF,0};

    s.clear();

    for (int i=1;i<=n;++i){

        add (-2*v[i].first,dp[i-1] + patrat(v[i].first) - patrat(max(0,v[i-1].second - v[i].first + 1)), cnt[i-1]);

        pair <long long, long long> sol = query (v[i].second+1);

        dp[i] = sol.first + patrat (v[i].second+1) + lambda;
        cnt[i] = sol.second + 1;
    }

}

long long take_photos (int N, int M, int K, std::vector <int> r, std::vector <int> c){
    n = N, m = M, k = K;
    for (i=0;i<n;++i)
        v[i+1] = make_pair(min(r[i],c[i])+1,max(r[i],c[i])+1);

    sort (v+1,v+n+1,cmp);

    /// elimin intervalele care sunt incluse in altele
    int St = -1, Dr = -1, el = 0;
    for (i=1;i<=n;++i){
        if (!(v[i].first >= St && v[i].second <= Dr)){
            v[++el] = v[i];
            St = v[i].first, Dr = v[i].second;
        }}

    n = el;

    k = min (k,n);

    long long st = 0, dr = INF;
    while (st <= dr){
        long long lambda = (st + dr)>>1;
        solve (lambda);
        if (cnt[n] > k)
            st = lambda + 1;
        else dr = lambda - 1;
    }

    solve (st);
    return dp[n] - k * st;

}

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 9 / 9
• Subtask 4: 16 / 16
• Subtask 5: 19 / 19
• Subtask 6: 0 / 40