oj.uz

Submission #656288

# Submission time Handle Problem Language Result Execution time Memory
656288 2022-11-06T17:47:37 Z chjiao Mobile (BOI12_mobile) C++14
0 / 100
 8 ms 428 KB 
#include <bits/stdc++.h>
using namespace std;

#define fastio	ios_base::sync_with_stdio(false);cin.tie(0)
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()

#define FOR(i,a,b) for(ll i=a;i<=b;i++)
#define FORB(i,a,b) for(ll i=a;i>=b;i--)

#define getbit(mask,i) ((mask>>(i))&1)
#define getnum(i) (1<<(i))

#define endl "\n"
#define sz(x) (int)size(x)
#define mp make_pair
using ll = long long;
const ll MOD1 = 1e9+7;
const ll MOD2 = 998244353;
const ll MN = 1e5;


//first true float/double
long double FLOAT_ERR = 1e-9;
long double first_true_float(long double lo, long double hi, function<bool(long double)> f) {
	// if none of the values in the range work, return hi + 1
	lo--;
	hi++;
	while (hi-lo > FLOAT_ERR) {
		long double mid =  (lo + hi) / 2.0f;
		if (f(mid)) {
			hi = mid;
		} else {
			lo = mid;
		}
	}
	return lo;
}

int main() {
    fastio;
	freopen("XXX.in","r",stdin);
	// freopen("XXX.out","w",stdout);
	
	ll N, L;
	cin >> N >> L;
	vector<pair<ll, ll>> stations(N);
	FOR(i,0,N-1) {
		ll y;
		cin >> stations[i].first >> y;
		stations[i].second = y*y;
	}
	long double ans = first_true_float(0, 4e9, [&](long double mid) { 
		long double mn=0, mx=L;
		long double dd=mid*mid, xx;
		for(auto station:stations) {
			if(dd-station.second<0) return false;
			xx=sqrt(dd-station.second);
			// if (station.first - xx>L) return false;
			// if(station.first+xx<0) return false;

			mn = max(mn, station.first - xx);
			mx = min(mx, station.first + xx);
		}
		return mx >= mn;
	});
	cout <<  fixed << setprecision(6) << ans << endl;



}

Compilation message

mobile.cpp: In function 'int main()':
mobile.cpp:43:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |  freopen("XXX.in","r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 8 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #7
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #8
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #9
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #10
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #11
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #12
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #13
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 360 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #14
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #15
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #16
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #17
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #18
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 428 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #19
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 340 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #20
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 316 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #21
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 384 KB Output isn't correct
2 Halted 0 ms 0 KB -