Codeforces 1244E. Minimizing Difference

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
using namespace std;
typedef long long ll;
inline ll read()
{
    ll x=0,f=1; char ch=getchar();
    while(ch<‘0‘||ch>‘9‘) { if(ch==‘-‘) f=-1; ch=getchar(); }
    while(ch>=‘0‘&&ch<=‘9‘) { x=(x<<1)+(x<<3)+(ch^48); ch=getchar(); }
    return x*f;
}
const int N=1e5+7;
ll n,m,A[N],ans;
int main()
{
    n=read(),m=read();
    for(int i=1;i<=n;i++) A[i]=read();
    sort(A+1,A+n+1); ans=A[n]-A[1];
    for(int i=1;i<(n/2)+(n&1);i++)
    {
        ll t=min(A[i+1]-A[i] + A[n-i+1]-A[n-i] , m/i);
        ans-=t; m-=t*i;
    }
    if(!(n&1))
    {
        ll t=min(A[n/2+1]-A[n/2], m/(n/2) );
        ans-=t; m-=t*(n/2);
    }
    printf("%lld\n",ans);
    return 0;
}