Submission #367597

#	Time	Username	Problem	Language	Result	Execution time	Memory
367597		Sparky_09	Sure Bet (CEOI17_sure)	C++17	100 / 100	708 ms	2168 KiB

sure

#include "bits/stdc++.h"
using namespace std;
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define trav(a, x) for(auto& a : x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<ll, ll> pii;
typedef vector<ll> vi;
typedef vector<pii> vpi;

template <class T>
void rd(T &x) {
	int sgn = 1;
	char ch;
	x = 0;
	for (ch = getchar(); (ch < '0' || ch > '9') && ch != '-'; ch = getchar()) ;
	if (ch == '-') ch = getchar(), sgn = -1;
	for (; '0' <= ch && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
	x *= sgn;
}
template <class T>
void wr(T x) {
	if (x < 0) putchar('-'), wr(-x);
	else if (x < 10) putchar(x + '0');
	else wr(x / 10), putchar(x % 10 + '0');
}

template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }

void usaco(string s){
  freopen((s+".in").c_str(), "r", stdin);
  freopen((s+".out").c_str(), "w", stdout);
}

int n;
double ans = 0;
vector<double> A, B;

int main() {
#ifdef LOCAL_DEFINE
	freopen("input.txt", "r", stdin);
#endif
  cin >> n;
  rep(i, 1, n+1){
    double a, b;
    cin >> a >> b;
    A.push_back(a);
    B.push_back(b);
  }
  sort(A.begin(), A.end(), greater<double>());
  sort(B.begin(), B.end(), greater<double>());
  rep(i, 1, n){ A[i] += A[i-1]; B[i] += B[i-1]; }
  rep(i, 1, 2*n+1){
    double l = 0, r = 1e8;
    while(r - l > 1e-5){
      double mid = (l + r)/2;
      int pos1 = lower_bound(A.begin(), A.end(), mid) - A.begin(), pos2 = lower_bound(B.begin(), B.end(), mid) - B.begin();
      if(A.back() >= mid and B.back() >= mid and pos1 + pos2 + 2 <= i) l = mid;
      else r = mid;
    }
    ans = max(ans, l - i);
  }
  printf("%.4f\n", ans);
}

Compilation message (stderr)

sure.cpp: In function 'void usaco(std::string)':
sure.cpp:33:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   33 |   freopen((s+".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sure.cpp:34:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   34 |   freopen((s+".out").c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 40 / 40