Language: C++

#include<bits/stdc++.h>

#define ll long long int
#define hell 998244353
#define vi vector <ll>
#define pb push_back
#define pii pair<ll,ll>
#define vii vector <pii>
#define rep(i,a,b)  for(ll i=a;i<b;i++)
#define sep(i,a,b)  for(ll i=a-1;i>=b;i--)
#define inf (ll)(1e16)

using namespace std;

void solve(){
    ll n,k;
    cin>>n>>k;
    vi a(n),dp(n+1,inf);
    rep(i,0,n)
        cin>>a[i];
    if(n==1)
    {
        cout<<0;
        return;
    }
    dp[0]=0;
    dp[1]=abs(a[1]-a[0]);
    rep(i,2,n)
    {
        sep(j,i,max(0,i-k))
            dp[i]=min(dp[i],dp[j]+abs(a[i]-a[j]));
    }
    cout<<dp[n];
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    ll t=1;
    //cin>>t;
    while(t--)
        solve();
    return 0;
}


Compiler output:
a.cc: In function 'void solve()':
a.cc:30:20: error: no matching function for call to 'max(int, long long int)'
   30 |         sep(j,i,max(0,i-k))
      |                 ~~~^~~~~~~
a.cc:10:37: note: in definition of macro 'sep'
   10 | #define sep(i,a,b)  for(ll i=a-1;i>=b;i--)
      |                                     ^
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:30:20: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   30 |         sep(j,i,max(0,i-k))
      |                 ~~~^~~~~~~
a.cc:10:37: note: in definition of macro 'sep'
   10 | #define sep(i,a,b)  for(ll i=a-1;i>=b;i--)
      |                                     ^
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:30:20: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   30 |         sep(j,i,max(0,i-k))
      |                 ~~~^~~~~~~
a.cc:10:37: note: in definition of macro 'sep'
   10 | #define sep(i,a,b)  for(ll i=a-1;i>=b;i--)
      |                                     ^