Codeforces-SolutionsA/Codes/492 B - Vanya and Lanterns/492B.cpp

59 lines
1.8 KiB
C++
Raw Normal View History

2023-08-31 02:12:14 +08:00
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ul unsigned long long
#define pb push_back
#define ss second
#define ff first
#define fr(m) for(int i=0; i<m; ++i)
#define fro(m) for(int i=1; i<m; ++i)
#define frj(m) for(int j=0; j<m; ++j)
#define frr(n) for(int i=n; i>=0; --i)
#define nl '\n'
#define yes cout<<"YES"<<nl
#define no cout<<"NO"<<nl
#define all(x) x.begin(), x.end()
#define dbg(x) cerr << #x <<" "<< x << endl;
#define fast_io (ios_base:: sync_with_stdio(false),cin.tie(NULL));
ll fact(ll n){ if(n==0) return 1; ll res = 1; for (ll i = 2; i <= n; i++) res = res * i; return res;}
ll nPr(ll n, ll r) { return fact(n) / fact(n - r); }
ll nCr(ll n, ll r) { return fact(n) / (fact(r) * fact(n - r)); }
ll gcd(ll a, ll b) { if (b == 0) return a; return gcd(b, a % b); }
ll lcm(ll a, ll b) { return (a * b) / gcd(a, b);}
ll mypow(ll a, ll b){ ll ans = 1; while(b){ if (b&1) ans = (ans*a) ; b /= 2; a = (a*a); } return ans; }
bool isPrime(ll n) { if(n <= 1) return false; for(ll i = 2; i <= sqrt(n); i++) if(n % i == 0) return false; return true;}
#define PI 3.141592653589793238;
#define INF LONG_LONG_MAX;
#define MOD 1e9+7;
//////////////////////////////////Code Start/////////////////////////////////////
void solve()
{
int n,l;
cin>>n>>l;
vector<int>lamps(n);
fr(n)
cin>>lamps[i];
int mx=0;
sort(all(lamps));
fro(n)
{
int x=lamps[i]-lamps[i-1];
mx=max(x,mx);
}
cout<<showpoint<<fixed<<setprecision(10);
double dis=max(lamps[0]-0, l - lamps[n - 1]);
cout<<max(dis,(double)mx/2)<<nl;
}
int main()
{
fast_io;
int TC = 1;
//cin >> TC;
while (TC--) solve();
}