Submission #821423

#	Time	Username	Problem	Language	Result	Execution time	Memory
821423		bane	Aliens (IOI16_aliens)	C++17	4 / 100	2 ms	1884 KiB

aliens

    #include <iostream>
    #include <cstdio>
    #include <cstdlib>
    #include <algorithm>
    #include <cmath>
    #include <vector>
    #include <set>
    #include <map>
    #include <unordered_set>
    #include <unordered_map>
    #include <queue>
    #include <ctime>
    #include <cassert>
    #include <complex>
    #include <string>
    #include <cstring>
    #include <chrono>
    #include <random>
    #include <bitset>
    #include <array>
    #include <iomanip>
    using namespace std;
     
    //#pragma GCC optimize("O3,unroll-loops")
    //#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
     
    /*
    #include <ext/pb_ds/assoc_container.hpp>
    using namespace __gnu_pbds;
    template <class T>
    using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
    */
     
     
    #define rep(i, n) for (int i = 0; i < (n); ++i)
    #define rep1(i, n) for (int i = 1; i < (n); ++i)
    #define rep1n(i, n) for (int i = 1; i <= (n); ++i)
    #define repr(i, n) for (int i = (n) - 1; i >= 0; --i)
     
     
    #define fr first
    #define sc second
    #define pb push_back
    #define mp make_pair
    #define all(x) (x).begin(), (x).end()
    #define rall(x) (x).rbegin(), (x).rend()
    #define endl '\n'
     
     
    using lint = long long;
    using ulint = unsigned long long;
    using ld = long double;
    using str = string;
    using pi = pair<int, int>;
     
     
    using vi = vector<int>;
    using vl = vector<lint>;
    using vpi = vector<pair<int, int>>;
    using vvi = vector<vi>;
     
    const int mod = (int)1e9 + 7;
     
    vector<pair<lint,lint>> unq;
    vector<lint> W(200000);
     
    struct CHT{
        struct Line{
            lint m,y;
            Line(lint a, lint b): m(a), y(b){}
     
            lint eval(lint x){
                return x * m + y;
            }
     
            lint intercept(Line& b){
                //m2x + c2 = m1x + c1
                //x * (m2 - m1) = c1 - c2
                //x = (c1 - c2) / (m2 - m1)
                return (y - b.y + (b.m - m - 1)) / (b.m - m);
            }
        };
        deque<pair<Line,pair<lint,lint>>>dq;
     
        void insert(lint m, lint y, int c){
            Line New_Line(m,y);
            while(dq.size() > 1){
                if (dq[dq.size() - 2].fr.intercept(New_Line) <= dq.back().sc.fr){
                    dq.pop_back();
                }else{
                    break;
                }
            }
     
            if (dq.empty()){
                dq.push_back({New_Line, {-(lint)1e14,c}});
            }else{
                dq.push_back({New_Line, {New_Line.intercept(dq.back().fr),c}});
            }
        }
     
        pair<lint,lint>query(lint x){
            while(dq.size() > 1 && dq[1].sc.fr <= x)dq.pop_front();
            return {dq[0].fr.eval(x), dq[0].sc.sc + 1};
        }
    };
     
    pair<lint,lint> Lagrangian_Relaxation(lint lambda){
        pair<lint,lint> dp[unq.size()];
        CHT cht;
        rep(i,(int)unq.size()){
            if(i){
                cht.insert(-2 * unq[i].fr, unq[i].fr * unq[i].fr - W[i-1] * W[i - 1] - 2 * unq[i].fr + dp[i - 1].fr + lambda, dp[i-1].sc);
                dp[i] = cht.query(unq[i].sc);
                dp[i].fr += 1 + 2 * unq[i].sc + unq[i].sc * unq[i].sc;
            }else{
                dp[i].fr = lambda + (unq[i].second - unq[i].first + 1) * (unq[i].second - unq[i].first + 1);
                dp[i].sc = 1;
            }
            
        }
        return dp[unq.size() - 1];
    }
     
    long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
        
        vector<pair<lint,lint>> Segments;
        rep(i,n){
            Segments.push_back(mp(min(r[i], c[i]), max(r[i], c[i])));
        }
        sort(all(Segments), [&](auto x, auto y){
            if (x.fr < y.fr)return true;
            else if (x.fr == y.fr)return x.sc > y.sc;
            else return false;
        });
     
        int most_right = -1;
        vi marked(n,0);
        rep(i,n){
            if (most_right >= Segments[i].sc){
                marked[i] = 1;
            }
            most_right = max((lint)most_right, Segments[i].second);
        }
        rep(i,n){
            if (!marked[i]){
                unq.pb(Segments[i]);
            }
        }
        rep1(i,(int)unq.size()){
            W[i - 1] = 0;
            if (unq[i - 1].sc - unq[i].fr >= 0)W[i-1] =unq[i - 1].sc - unq[i].fr + 1; 
        }
        W[unq.size() - 1] = 0;
        lint L = 0, R = (lint)1e12;
     
        while(L <= R){
            lint mid = (L+R) / 2;
            if (Lagrangian_Relaxation(mid).sc <= k){
                R = mid - 1;
            }else{
                L = mid + 1;
            }
        }
        return Lagrangian_Relaxation(R+1).fr - (R + 1) * k;
    }

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