不太清楚哪裡來的題……反正我管它叫變態排序題

題解是別人給的

#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
const int N = 1E7+10;
struct node{
	double left,right;
	double minn,maxn;
}seg[N];
double num[N];
const double inf = 0x3f3f3f3f3f3f3f;
int main(){
	int n;
	cin>>n;
	double
 
 minn = inf;
	double maxn = -inf;
	int minid;
	int maxid;
	for(int i=0;i<n;i++){
		scanf("%lf",&num[i]);
		if(maxn < num[i]){
			maxn = num[i];
			maxid = i;
		}
		if(minn > num[i]){
			minn = num[i];
			minid = i;
		}
	}
//	printf("%lf %lf\n",minn,maxn);
	double evl = (maxn - minn)/(double
 
)(n-1);
//	printf("%lf\n",evl);
	for(int i=1;i<=n-1;i++){
		seg[i].left = minn;
		seg[i].right = minn + evl;
		minn += evl;
		seg[i].maxn = -inf;
		seg[i].minn = inf;
	}
	seg[1].left = minn;
	seg[n-1].right = maxn;
	maxn = evl;
	for(int i=0;i<n;i++){
		int id = (num[i] - num[minid])/evl + 1;
		seg[
 
id].maxn = max(seg[id].maxn,num[i]);
		seg[id].minn = min(seg[id].minn,num[i]);
	}
/*
	for(int i=1;i<=n-1;i++){
		printf("%lf %lf\n",seg[i].minn,seg[i].maxn);
	}
*/
	for(int i=2;i<n-1;i++){
		if(seg[i].minn == inf){
			seg[i].minn = seg[i].maxn = seg[i-1].maxn;
		}
	}
/*
	for(int i=1;i<=n-1;i++){
		printf("%lf %lf\n",seg[i].minn,seg[i].maxn);
	}
*/
	for(int i=2;i<=n-1;i++){
		maxn = max(maxn,seg[i].minn - seg[i-1].maxn);
	}
	printf("%lf\n",maxn);
	return 0;
}
/*
5
2.1  3.1  7.5  1.5  6.3

*/