Submission #957609

#	Time	Username	Problem	Language	Result	Execution time	Memory
957609		onlk97	Aliens (IOI16_aliens)	C++14	100 / 100	857 ms	22416 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>
using namespace std;
int n;
vector <pair <__int128,__int128> > v;
struct Line{
    mutable __int128 m,c,p;
    bool operator<(const Line&o) const {
        return m<o.m;
    };
    bool operator<(__int128 val) const {
        return p<val;
    };
};
struct LineContainer:multiset <Line,less<> > {
    const __int128 inf=1e36;
    __int128 div(__int128 a,__int128 b){
        return a/b-((a^b)<0&&a%b);
    }
    bool intrs(iterator a,iterator b){
        if (b==end()) return a->p=inf,0;
        if (a->m==b->m) a->p=(a->c>b->c?inf:-inf);
        else a->p=div(b->c-a->c,a->m-b->m);
        return a->p>=b->p;
    }
    void addline(__int128 m,__int128 c){
        auto z=insert({-m,-c,0});
        auto a=z++;
        auto b=a;
        while (intrs(b,z)) z=erase(z);
        if (a!=begin()&&intrs(--a,b)) intrs(a,b=erase(b));
        while ((b=a)!=begin()&&(--a)->p>=b->p) intrs(a,erase(b));
    }
    __int128 query(__int128 val){
        auto l=*lower_bound(val);
        return -l.m*val-l.c;
    }
};
const __int128 C=2e5;
__int128 dp[100010];
pair <long long,long long> calc(__int128 add){
    LineContainer lc;
    dp[0]=0;
    lc.addline(C*-2*v[1].first,C*(v[1].first-1)*(v[1].first-1)+C*add+1);
    for (int i=1; i<=n; i++){
        dp[i]=lc.query(v[i].second)+C*v[i].second*(v[i].second+2);
        if (i<n){
            __int128 tp=max((__int128)0,v[i].second-v[i+1].first+1);
            lc.addline(C*-2*v[i+1].first,dp[i]-C*tp*tp+C*(v[i+1].first-1)*(v[i+1].first-1)+C*add+1);
        }
    }
    return {dp[n]/C-(dp[n]%C)*add,dp[n]%C};
} 
long long take_photos(int N,int m,int k,vector <int> r,vector <int> c){
    int til[m];
    for (int i=0; i<m; i++) til[i]=i-1;
    for (int i=0; i<N; i++){
        int rr=r[i],cc=c[i];
        if (rr>cc) swap(rr,cc);
        til[rr]=max(til[rr],cc);
    }
    int mx=-1;
    for (int i=0; i<m; i++){
        if (til[i]>mx&&i<=til[i]){
            v.push_back({i,til[i]});
            mx=til[i];
        }
    }
    n=v.size();
    v.insert(v.begin(),{0,0});
    long long L=0,R=1e12;
    while (L<R){
        long long mid=(L+R)/2;
        if (calc(mid).second>k) L=mid+1;
        else R=mid;
    }
    pair <long long,long long> cur=calc(L);
    if (cur.second==k) return cur.first;
    pair <long long,long long> nxt=calc(L-1);
    if (nxt.second==cur.second) return cur.first;
    return cur.first+(k-cur.second)*(nxt.first-cur.first)/(nxt.second-cur.second);
}

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