Submission #821921

#	Time	Username	Problem	Language	Result	Execution time	Memory
821921		bane	Aliens (IOI16_aliens)	C++17	100 / 100	171 ms	10948 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;
            vl 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)) / (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() - 1].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 + 0};
                }
            };
             
            pair<lint,lint> Lagrangian_Relaxation(lint lambda, lint k){
                        CHT vals;
                        vector<long long> dp(unq.size()+1);
                        vector<int> cnt(unq.size()+1);
                        for(int i = 1;i<=unq.size();i++){
                            long long val = dp[i-1] + unq[i-1].second * unq[i-1].second - 2*unq[i-1].second;
                            if(i > 1)
                                val -= max(0ll,unq[i-2].first - unq[i-1].second + 1) *  max(0ll,unq[i-2].first - unq[i-1].second + 1);
                            
                            vals.insert(-2*unq[i-1].second,val,cnt[i-1]);
                            auto x = vals.query(unq[i-1].first);
                            dp[i] = x.first + unq[i-1].first * unq[i-1].first + 2 * unq[i-1].first + 1 + lambda;
                            cnt[i] = x.second + 1;
                        } 
                        return make_pair(cnt[unq.size()],dp[unq.size()] - k * lambda);
                    
                
            }
             
            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]);
                    }
                }
                for (auto& i : unq){
                    swap(i.fr,i.sc);
                }
                lint L = 0, R = (lint)m*m;
                while(L < R){
                    lint mid = (L+R) / 2;
                    if (Lagrangian_Relaxation(mid,k).fr <= k){
                        R = mid;
                    }else{
                        L = mid + 1;
                    }
                }
                return Lagrangian_Relaxation(L,k).sc;
            }

Compilation message (stderr)

aliens.cpp: In function 'std::pair<long long int, long long int> Lagrangian_Relaxation(lint, lint)':
aliens.cpp:112:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  112 |                         for(int i = 1;i<=unq.size();i++){
      |                                       ~^~~~~~~~~~~~

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