Submission #349668

#	Time	Username	Problem	Language	Result	Execution time	Memory
349668		silverfish	Balloons (CEOI11_bal)	C++14	100 / 100	352 ms	12652 KiB

bal

#include <bits/stdc++.h>
using namespace std;

/*<DEBUG>*/
#define tem template <typename 
#define can_shift(_X_, ...) enable_if_t<sizeof test<_X_>(0) __VA_ARGS__ 8, debug&> operator<<(T i)
#define _op debug& operator<<
tem C > auto test(C *x) -> decltype(cerr << *x, 0LL);
tem C > char test(...);
tem C > struct itr{C begin, end; };
tem C > itr<C> get_range(C b, C e) { return itr<C>{b, e}; }
struct debug{
#ifdef _LOCAL
	~debug(){ cerr << endl; }
	tem T > can_shift(T, ==){ cerr << boolalpha << i; return *this; }
	tem T> can_shift(T, !=){ return *this << get_range(begin(i), end(i)); }
	tem T, typename U > _op (pair<T, U> i){ 
		return *this << "< " << i.first << " , " << i.second << " >"; }
	tem T> _op (itr<T> i){
		*this <<  "{ ";
		for(auto it = i.begin; it != i.end; it++){
			*this << " , " + (it==i.begin?2:0) << *it;
		}
		return *this << " }";
	}
#else
tem T> _op (const T&) { return *this; }
#endif 
};

string _ARR_(int* arr, int sz){
	string ret = "{ " + to_string(arr[0]); 
	for(int i = 1; i < sz; i++) ret += " , " +  to_string(arr[i]);
	ret += " }"; return ret;
}

#define exp(...) " [ " << #__VA_ARGS__ << " : " << (__VA_ARGS__) << " ]"
/*</DEBUG>*/

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef pair<int, int> pii;
//mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

#define pb push_back
#define FAST ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define TC int __TC__; cin >> __TC__; while(__TC__--)
#define ar array

const int INF = 1e9 + 7, N = 2e5;

ld r[N], x[N]; 
int n;
int best[N];

ld getdiff(int i, int j){
	return (x[j] - x[i])*(x[j] - x[i])/(4*r[i]);	
}

void find_first(int i, int j, int cur){
	int lo = cur, hi = n-1; 
	if(getdiff(i, n-1) < getdiff(j, n-1)) return;

	while(hi - lo > 0){
		int m = (lo + hi) / 2;
		if(getdiff(i, m) < getdiff(j, m)) lo = m+1;
		else hi = m;
	}

	if(~best[lo]){
		if(getdiff(j, lo) < getdiff(best[lo], lo)){
			find_first(j, best[lo], lo);
			best[lo] = j;	
		}else{
			find_first(best[lo],j, lo);
		}
	}else{
		best[lo] = j;	
	}
	return;
}

int main(void)
{
	FAST;
	cout << fixed << setprecision(3);
	cin >> n;
	fill(best, best+n, -1);
	for(int i = 0; i < n; ++i){
		cin >> x[i] >> r[i];
	}
	cout << r[0] << '\n';
	r[1] = min(r[1], getdiff(0, 1));
	cout << r[1] << '\n';
	best[1] = 0;

	for(int i = 2; i < n; ++i){

		vector<pair<ld, int>> v;
		if(~best[i]) v.pb({getdiff(best[i], i), best[i]});
		v.pb({getdiff(i-1, i), i-1});
		v.pb({getdiff(best[i-1], i), best[i-1]});

		sort(v.begin(), v.end());

		find_first(v[0].second, v[1].second, i);	
		if(~best[i]) find_first(v[0].second, v[2].second, i);
		best[i] = v[0].second;
		
		r[i] = min(r[i], getdiff(best[i], i));

		cout << r[i] << '\n';
	}

	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10