Submission #135949

#	Time	Username	Problem	Language	Result	Execution time	Memory
135949		ckodser	Aliens (IOI16_aliens)	C++14	4 / 100	8 ms	2296 KiB

aliens

#include "aliens.h"
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif
#define ll int
#define pb push_back
#define mp make_pair
#define ld long double
#define F first
#define S second
#define pii pair<ll,ll>

using namespace :: std;

const ll maxn=4100;
const ll maxk=4010;
const ll inf=1e9+900;
ll tav2(ll x){return x*x;}
ll sagh(ll a,ll b){
	return (a+b-1)/b;
}

pii khat[maxn];
vector<pii> cht;
ll poi;

ll barkhord(ll a,ll b){
	return sagh((khat[a].F-khat[b].F),(khat[b].S-khat[a].S));
}
void add(ll x[],ll v[],ll n){
	poi=0;
	for(ll i=0;i<n;i++){
		khat[i]=mp(x[i],v[i]);
	}
	cht.clear();
	cht.pb(mp(0,0));
	for(ll i=1;i<n;i++){
		while(cht.size() && barkhord(cht.back().F,i)<=cht.back().S)cht.pop_back();
		if(cht.empty()){
			cht.pb(mp(i,0));
		}else{
			cht.pb(mp(i,barkhord(cht.back().F,i)));
		}
	}
	/*
	for(ll i=0;i<n;i++){
		cout<<x[i]<<' '<<v[i]<<"   ";
	}
	cout<<endl;
	for(auto v:cht){
		cout<<v.F<<' '<<v.S<<" :  ";
	}
	cout<<endl;*/
}
ll findMinAt(ll t){
	while(poi<cht.size()-1 && cht[poi+1].S<=t)poi++;
	ll v=cht[poi].F;
	return khat[v].F+khat[v].S*t;
}

ll dp[maxn][maxk];
vector<pii> vec;


ll XX[maxn];
ll X[maxn];
ll V[maxn];

ll mx[maxn];
long long take_photos(int n, int m, int k, vector<int> r, vector<int> c) {
	swap(n,m);
	fill(mx,mx+maxn,inf);

	for(ll i=0;i<m;i++){
		if(c[i]>r[i]){
			swap(c[i],r[i]);
		}
		mx[r[i]]=min(mx[r[i]],(ll)c[i]);
	}
	stack<ll> stk;
	for(ll i=0;i<n;i++){
		while(stk.size() && mx[stk.top()]>=mx[i]){
			stk.pop();
		}
		if(mx[i]!=inf){
			stk.push(i);
		}	
	}
	while(stk.size()){
		vec.pb(mp(stk.top(),mx[stk.top()]));
		stk.pop();
	}
	sort(vec.begin(),vec.end());

	XX[0]=tav2(vec[0].S);
	V[0]=vec[0].S*-2;
	for(ll i=0;i+1<vec.size();i++){
		XX[i+1]=-tav2(max(0,vec[i].F-vec[i+1].S+1))+tav2(vec[i+1].S);
		V[i+1]=vec[i+1].S*-2;
	}
	for(ll i=0;i<vec.size();i++){
		vec[i].F++;
	}
	for(ll i=0;i<vec.size();i++){
		dp[i][0]=inf;
	}
	for(ll j=1;j<=k;j++){
		X[0]=XX[0];
		for(ll i=1;i<vec.size();i++){
			X[i]=XX[i]+dp[i-1][j-1];
		}
		add(X,V,vec.size());
		for(ll i=0;i<vec.size();i++){
			dp[i][j]=findMinAt(vec[i].F)+tav2(vec[i].F);
		}
	}
	return dp[vec.size()-1][k];
}

Compilation message (stderr)

aliens.cpp: In function 'int findMinAt(int)':
aliens.cpp:106:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(poi<cht.size()-1 && cht[poi+1].S<=t)poi++;
        ~~~^~~~~~~~~~~~~
aliens.cpp: In function 'long long int take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:147:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ll i=0;i+1<vec.size();i++){
             ~~~^~~~~~~~~~~
aliens.cpp:151:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ll i=0;i<vec.size();i++){
             ~^~~~~~~~~~~
aliens.cpp:154:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ll i=0;i<vec.size();i++){
             ~^~~~~~~~~~~
aliens.cpp:159:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(ll i=1;i<vec.size();i++){
              ~^~~~~~~~~~~
aliens.cpp:163:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(ll i=0;i<vec.size();i++){
              ~^~~~~~~~~~~

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