题解

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <cctype>
using namespace std;

int n,m,t[505],mem[505][505];
int solve(int i,int st){
if (i==n+1)
return 0;
if (st<t[i])
return solve(i,t[i]);
if (mem[i][st-t[i]])
return mem[i][st-t[i]];
int sum=0,j=i;

while (j<=n && t[j]<=st)
	sum+=t[j++];
int best=st*(j-i)-sum+solve(j,st+m); 

for (;j<=n;j++){
	sum+=t[j];
	best=min(t[j]*(j-i+1)-sum+solve(j+1,t[j]+m),best);
}
return mem[i][st-t[i]]=best;

}

int main(){
cin>>n>>m;
for (int i=1;i<=n;i++)
cin>>t[i];
sort(t+1,t+n+1);
cout << solve(1,0) << endl;
return 0;
}