Problem p03274 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> l_l;
typedef pair<int, int> i_i;
typedef vector<ll> vel;
typedef vector<int> vei;
typedef vector<char> vec;
typedef vector<bool> veb;
typedef vector<string> ves;
typedef vector<vector<ll>> ve_vel;
typedef vector<vector<int>> ve_vei;
typedef vector<vector<char>> ve_vec;
typedef vector<vector<bool>> ve_veb;
typedef vector<vector<string>> ve_ves;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i < (int)(n); i++)
#define rep2(i, n) for (int i = 2; i < (int)(n); i++)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define fs first
#define sc second
#define pub push_back
#define puf push_front
#define pob pop_back
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define maxel(a) *max_element(all(a))
#define minel(a) *min_element(all(a))
#define acc accumulate
#define EPS (1e-7)
#define INF (1e9)
#define PI (acos(-1))
#define mod (1000000007)
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

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

  int N, K;
  cin >> N >> K;
  vel x(N);
  rep(i, N) cin >> x[i];

  ll ans = INF;
  rep(i, N) {
    ll temp = abs(x[i]) + abs(x[i + K - 1] - x[i]);
    ans = min(ans, temp);
  }
  cout << ans << endl;
  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> l_l;
typedef pair<int, int> i_i;
typedef vector<ll> vel;
typedef vector<int> vei;
typedef vector<char> vec;
typedef vector<bool> veb;
typedef vector<string> ves;
typedef vector<vector<ll>> ve_vel;
typedef vector<vector<int>> ve_vei;
typedef vector<vector<char>> ve_vec;
typedef vector<vector<bool>> ve_veb;
typedef vector<vector<string>> ve_ves;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i < (int)(n); i++)
#define rep2(i, n) for (int i = 2; i < (int)(n); i++)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define fs first
#define sc second
#define pub push_back
#define puf push_front
#define pob pop_back
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define maxel(a) *max_element(all(a))
#define minel(a) *min_element(all(a))
#define acc accumulate
#define EPS (1e-7)
#define INF (1e9)
#define PI (acos(-1))
#define mod (1000000007)
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

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

  int N, K;
  cin >> N >> K;
  vel x(N);
  rep(i, N) cin >> x[i];

  ll ans = INF;
  rep(i, N - K + 1) {
    if (abs(x[i]) < abs(x[i + K - 1])) {
      ll temp = abs(x[i]) + abs(x[i + K - 1] - x[i]);
      ans = min(ans, temp);
    } else {
      ll temp = abs(x[i + K - 1]) + abs(x[i + K - 1] - x[i]);
      ans = min(ans, temp);
    }
  }
  cout << ans << endl;
  return 0;
}