Problem p03161 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <stack>
#include <string>
#include <vector>

#define MOD (1000000007)

using namespace std;

typedef long long ll;
typedef pair<ll, ll> tup;
const int MAX = 510000;

long long fac[MAX], finv[MAX], inv[MAX];

ll modpow(ll a, ll n, ll mod) {
  ll res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

// テーブルを作る前処理
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}

// 二項係数計算
long long COM(int n, int k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

template <typename T>
bool next_combination(const T first, const T last, int k) {
  const T subset = first + k;
  // empty container | k = 0 | k == n
  if (first == last || first == subset || last == subset) {
    return false;
  }
  T src = subset;
  while (first != src) {
    src--;
    if (*src < *(last - 1)) {
      T dest = subset;
      while (*src >= *dest) {
        dest++;
      }
      iter_swap(src, dest);
      rotate(src + 1, dest + 1, last);
      rotate(subset, subset + (last - dest) - 1, last);
      return true;
    }
  }
  // restore
  rotate(first, subset, last);
  return false;
}

int main() {
  ll N, K;
  cin >> N >> K;

  vector<ll> h(N);
  for (ll i = 0; i < N; i++)
    cin >> h[i];

  vector<ll> dp(N);
  dp[0] = 0;

  for (ll i = 1; i < N; i++) {
    ll temp = 999999999;
    for (ll j = 1; j <= K; j++)
      temp = min(temp, abs(h[i - j] - h[i]) + dp[i - j]);
    dp[i] = temp;
  }
  // for(ll i = 0; i < N-1; i++) {
  //     cout << dp[i] <<" " ;
  // }

  cout << dp[N - 1] << endl;
  return 0;
}


Fixed submission:
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <stack>
#include <string>
#include <vector>

#define MOD (1000000007)

using namespace std;

typedef long long ll;
typedef pair<ll, ll> tup;
const int MAX = 510000;

long long fac[MAX], finv[MAX], inv[MAX];

ll modpow(ll a, ll n, ll mod) {
  ll res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

// テーブルを作る前処理
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}

// 二項係数計算
long long COM(int n, int k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

template <typename T>
bool next_combination(const T first, const T last, int k) {
  const T subset = first + k;
  // empty container | k = 0 | k == n
  if (first == last || first == subset || last == subset) {
    return false;
  }
  T src = subset;
  while (first != src) {
    src--;
    if (*src < *(last - 1)) {
      T dest = subset;
      while (*src >= *dest) {
        dest++;
      }
      iter_swap(src, dest);
      rotate(src + 1, dest + 1, last);
      rotate(subset, subset + (last - dest) - 1, last);
      return true;
    }
  }
  // restore
  rotate(first, subset, last);
  return false;
}

int main() {
  ll N, K;
  cin >> N >> K;

  vector<ll> h(N);
  for (ll i = 0; i < N; i++)
    cin >> h[i];

  vector<ll> dp(N);
  dp[0] = 0;

  for (ll i = 1; i < N; i++) {
    ll temp = 999999999;
    for (ll j = 1; j <= min(K, i); j++)
      temp = min(temp, abs(h[i - j] - h[i]) + dp[i - j]);
    dp[i] = temp;
  }
  // for(ll i = 0; i < N-1; i++) {
  //     cout << dp[i] <<" " ;
  // }

  cout << dp[N - 1] << endl;
  return 0;
}