路灯照明

路灯照明 [(https://www.online1987.com/路灯照明/)]

#include<iostream>
#include<climits>
#include<vector>
#include<algorithm>
using namespace std;
int main() {
	int maxValue = 0;
	int n = 0;
	int l = 0;
	cin >> n >> l;
	vector<int> nums(n+1, 0);//vector只有初始化的元素可以赋值，如果vector不初始化，默认大小为0，对nums[i]赋值会报错.
	for (int i = 0; i<n&&cin >> nums[i]; ++i) {
		;
	}
	sort(nums.begin(), nums.end());
	for (int i = 0; i < n; ++i) {
		if (i == n - 1) maxValue = max(l - nums[i + 1], maxValue);
		maxValue = max(nums[i + 1] - nums[i], maxValue);
	}
	 cout<<(double)maxValue / 2<<endl;
	 return 0;
}