简单

#include<bits/stdc++.h>
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(void){
    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;
}