Problem p03161 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vb = vector<bool>;
using vvb = vector<vb>;
using vd = vector<double>;
using vvd = vector<vd>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using pll = pair<ll, ll>;
using tll = tuple<ll, ll>;
using tlll = tuple<ll, ll, ll>;
using vs = vector<string>;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define rep(i, n) range(i, 0, n)
#define rrep(i, n) for (ll i = (n)-1; i >= 0; i--)
#define range(i, a, n) for (ll i = (a); i < (n); i++)
#define LINF ((ll)1ll << 60)
#define INF ((int)1 << 30)
#define EPS (1e-9)
#define MOD (1000000007ll)
#define fcout(a) cout << setprecision(a) << fixed
#define fs first
#define sc second
#define PI (3.1415926535897932384)

int dx[] = {1, 0, -1, 0, 1, -1, -1, 1}, dy[] = {0, 1, 0, -1, 1, 1, -1, -1};
template <class T> bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class S> S sumvec(vector<S> &a) { return accumulate(all(a), S()); }
template <class S> S maxvec(vector<S> &a) { return *max_element(all(a)); }
template <class S> S minvec(vector<S> &a) { return *min_element(all(a)); }
ll max(int a, ll b) { return max((ll)a, b); }
ll max(ll a, int b) { return max(a, (ll)b); }
int sgn(const double &r) { return (r > EPS) - (r < -EPS); } // a>0  : sgn(a)>0
int sgn(const double &a, const double &b) {
  return sgn(a - b);
} // b<=c : sgn(b,c)<=0

template <class T> void puta(T &&t) { cout << t << "\n"; }
template <class H, class... T> void puta(H &&h, T &&...t) {
  cout << h << ' ';
  puta(t...);
}
template <class S, class T> void tf(bool b, S t, T f) {
  if (b)
    puta(t);
  else
    puta(f);
}
void YN(bool b) { tf(b, "YES", "NO"); }
void Yn(bool b) { tf(b, "Yes", "No"); }
void yn(bool b) { tf(b, "yes", "no"); }
template <class S, class T> ostream &operator<<(ostream &os, pair<S, T> p) {
  os << "[" << p.first << ", " << p.second << "]";
  return os;
};
template <class S> auto &operator<<(ostream &os, vector<S> t) {
  bool a = 1;
  for (auto s : t) {
    os << (a ? "" : " ") << s;
    a = 0;
  }
  return os;
}
template <class S> auto &operator>>(istream &is, vector<S> &t) {
  for (S &a : t)
    cin >> a;
  return is;
}

vvl comb(ll n, ll r) {
  vvl v(n + 1, vl(n + 1, 0));
  for (ll i = 0; i < v.size(); i++) {
    v[i][0] = 1;
    v[i][i] = 1;
  }
  for (ll j = 1; j < v.size(); j++) {
    for (ll k = 1; k < j; k++) {
      v[j][k] = (v[j - 1][k - 1] + v[j - 1][k]);
    }
  }
  return v;
}

int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll n, k;
  cin >> n >> k;
  vl h(n);
  cin >> h;
  rep(i, k) { h.push_back(INF); }
  vl cost(n + k + 1, INF);
  cost[0] = 0;
  /*
  range(i,1,n){
      ll a,b=INF;
      a=abs(h[i]-h[i-1]) + cost[i-1];
      if(i>1) b=abs(h[i]-h[i-2]) + cost[i-2];
      //cout<<a<<" "<<b<<" ";
      cost[i]=min(a,b);
      //puta(cost[i]);
  }*/

  rep(i, n + k + 1) {
    range(j, 1, k + 1) {
      ll a = abs(h[i] - h[i + j]);
      // cout<<a<<" ";
      cost[i + j] = min(cost[i + j], cost[i] + a);
      // cout<<cost[i]<<" "<<cost[i+j]<<endl;
    }
  }

  puta(cost[n - 1]);
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vb = vector<bool>;
using vvb = vector<vb>;
using vd = vector<double>;
using vvd = vector<vd>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using pll = pair<ll, ll>;
using tll = tuple<ll, ll>;
using tlll = tuple<ll, ll, ll>;
using vs = vector<string>;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define rep(i, n) range(i, 0, n)
#define rrep(i, n) for (ll i = (n)-1; i >= 0; i--)
#define range(i, a, n) for (ll i = (a); i < (n); i++)
#define LINF ((ll)1ll << 60)
#define INF ((int)1 << 30)
#define EPS (1e-9)
#define MOD (1000000007ll)
#define fcout(a) cout << setprecision(a) << fixed
#define fs first
#define sc second
#define PI (3.1415926535897932384)

int dx[] = {1, 0, -1, 0, 1, -1, -1, 1}, dy[] = {0, 1, 0, -1, 1, 1, -1, -1};
template <class T> bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class S> S sumvec(vector<S> &a) { return accumulate(all(a), S()); }
template <class S> S maxvec(vector<S> &a) { return *max_element(all(a)); }
template <class S> S minvec(vector<S> &a) { return *min_element(all(a)); }
ll max(int a, ll b) { return max((ll)a, b); }
ll max(ll a, int b) { return max(a, (ll)b); }
int sgn(const double &r) { return (r > EPS) - (r < -EPS); } // a>0  : sgn(a)>0
int sgn(const double &a, const double &b) {
  return sgn(a - b);
} // b<=c : sgn(b,c)<=0

template <class T> void puta(T &&t) { cout << t << "\n"; }
template <class H, class... T> void puta(H &&h, T &&...t) {
  cout << h << ' ';
  puta(t...);
}
template <class S, class T> void tf(bool b, S t, T f) {
  if (b)
    puta(t);
  else
    puta(f);
}
void YN(bool b) { tf(b, "YES", "NO"); }
void Yn(bool b) { tf(b, "Yes", "No"); }
void yn(bool b) { tf(b, "yes", "no"); }
template <class S, class T> ostream &operator<<(ostream &os, pair<S, T> p) {
  os << "[" << p.first << ", " << p.second << "]";
  return os;
};
template <class S> auto &operator<<(ostream &os, vector<S> t) {
  bool a = 1;
  for (auto s : t) {
    os << (a ? "" : " ") << s;
    a = 0;
  }
  return os;
}
template <class S> auto &operator>>(istream &is, vector<S> &t) {
  for (S &a : t)
    cin >> a;
  return is;
}

vvl comb(ll n, ll r) {
  vvl v(n + 1, vl(n + 1, 0));
  for (ll i = 0; i < v.size(); i++) {
    v[i][0] = 1;
    v[i][i] = 1;
  }
  for (ll j = 1; j < v.size(); j++) {
    for (ll k = 1; k < j; k++) {
      v[j][k] = (v[j - 1][k - 1] + v[j - 1][k]);
    }
  }
  return v;
}

int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll n, k;
  cin >> n >> k;
  vl h(n);
  cin >> h;
  rep(i, k * 3) { h.push_back(INF); }
  vl cost(n + k * 3, INF);
  cost[0] = 0;
  /*
  range(i,1,n){
      ll a,b=INF;
      a=abs(h[i]-h[i-1]) + cost[i-1];
      if(i>1) b=abs(h[i]-h[i-2]) + cost[i-2];
      //cout<<a<<" "<<b<<" ";
      cost[i]=min(a,b);
      //puta(cost[i]);
  }*/

  rep(i, n + k + 1) {
    range(j, 1, k + 1) {
      ll a = abs(h[i] - h[i + j]);
      // cout<<a<<" ";
      cost[i + j] = min(cost[i + j], cost[i] + a);
      // cout<<cost[i]<<" "<<cost[i+j]<<endl;
    }
  }

  puta(cost[n - 1]);
}