Submission #135904

#	Time	Username	Problem	Language	Result	Execution time	Memory
135904		ckodser	Aliens (IOI16_aliens)	C++14	25 / 100	144 ms	3832 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 dp[maxn][maxk];
vector<pii> vec;


ll X[maxn];
ll cost(ll u,ll i){
	return -2*vec[i].F*vec[u+1].S+X[u];
}

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());
	for(ll i=0;i+1<vec.size();i++){
		X[i]=-tav2(max(0,vec[i].F-vec[i+1].S+1))+tav2(vec[i+1].S);
	}
	for(ll i=0;i<vec.size();i++){
		vec[i].F++;
	}

	for(ll i=0;i<vec.size();i++){
		dp[i][0]=inf;
		pii e=vec[i];
		for(ll j=1;j<=k;j++){
			dp[i][j]=tav2(vec[0].S)-2*vec[i].F*vec[0].S;
			for(ll u=0;u<i;u++){
				dp[i][j]=min(dp[i][j],dp[u][j-1]+cost(u,i));
			}
			dp[i][j]+=tav2(vec[i].F);
		}
	}
	return dp[vec.size()-1][k];
}

Compilation message (stderr)

aliens.cpp: In function 'long long int take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:107:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ll i=0;i+1<vec.size();i++){
             ~~~^~~~~~~~~~~
aliens.cpp:110:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ll i=0;i<vec.size();i++){
             ~^~~~~~~~~~~
aliens.cpp:114:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ll i=0;i<vec.size();i++){
             ~^~~~~~~~~~~
aliens.cpp:116:7: warning: variable 'e' set but not used [-Wunused-but-set-variable]
   pii e=vec[i];
       ^

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