求助月赛T4

#include<iostream>
#define int long long
using namespace std;
const int N=1e5+10;
int dp[N<<1],a[N],n,m;
int count_bit(int x){
	int res=0;
	while(x){
		res++;
		x&=x-1;
	}
	return res;
}
bool check(int x){
	if(count_bit(x)>m) return 0;
	for(int i=0;(1<<i)<x;i++){
		if((x & (1 << i)) && ( x & (1 << ( i+1 )))) return 0;
	}
	return 1;
}
signed main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	int ans=0x3f3f3f3f;
	for(int i=1;i<=(1<<(n+1))-1;i++){
		if(check(i)){
			int maxn=-0x3f3f3f3f,minn=-maxn;
			for(int j=0;j<=n;j++){
				if(i & (1<<j)){
					maxn=max(maxn,a[j]);
					minn=min(minn,a[j]);
				}
			}
			dp[i]=maxn-minn;
			if(count_bit(i)==m) ans=min(ans,dp[i]);
		}
	}
	cout<<ans<<endl;
}