Problem p03426 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;

const long long mod = 1e9 + 7;

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ull unsigned long long
#define ld long double
#define vi vector<int>
#define vll vector<ll>
#define vc vector<char>
#define vs vector<string>
#define vpii vector<pii>
#define vpll vector<pll>

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; i++)
#define rep1(i, n) for (int i = 1, i##_len = (n); i <= i##_len; i++)
#define repr(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define rep1r(i, n) for (int i = ((int)(n)); i >= 1; i--)

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define RSORT(x) sort(rall(x));
#define pb push_back
#define mp make_pair

#define INF (1e9)
#define PI (acos(-1))
#define EPS (1e-7)

ull gcd(ull a, ull b) { return b ? gcd(b, a % b) : a; }
ull lcm(ull a, ull b) { return a / gcd(a, b) * b; }

int main() {
  int h, w, d;
  cin >> h >> w >> d;
  vector<vi> a(h, vi(w));
  rep(i, h) rep(j, w) {
    cin >> a[i][j];
    a[i][j]--;
  }
  vector<vpii> b(d, vpii(h * w / d));
  rep(i, h) rep(j, w) b[(a[i][j]) % d][(a[i][j]) / d] = {i, j};
  vector<vll> sum(d, vll(h * w / d + 1));
  rep(i, d) rep1(j, sz(b[i]) - 1) {
    if (d * j + i >= h * w)
      continue;
    int cost = abs(b[i][j].first - b[i][j - 1].first) +
               abs(b[i][j].second - b[i][j - 1].second);
    sum[i][j] = sum[i][j - 1] + cost;
  }
  int q;
  cin >> q;
  rep(i, q) {
    int l, r;
    cin >> l >> r;
    --l;
    --r;
    ll ans = sum[l % d][r / d] - sum[l % d][l / d];
    cout << ans << endl;
  }
  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;

const long long mod = 1e9 + 7;

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ull unsigned long long
#define ld long double
#define vi vector<int>
#define vll vector<ll>
#define vc vector<char>
#define vs vector<string>
#define vpii vector<pii>
#define vpll vector<pll>

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; i++)
#define rep1(i, n) for (int i = 1, i##_len = (n); i <= i##_len; i++)
#define repr(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define rep1r(i, n) for (int i = ((int)(n)); i >= 1; i--)

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define RSORT(x) sort(rall(x));
#define pb push_back
#define mp make_pair

#define INF (1e9)
#define PI (acos(-1))
#define EPS (1e-7)

ull gcd(ull a, ull b) { return b ? gcd(b, a % b) : a; }
ull lcm(ull a, ull b) { return a / gcd(a, b) * b; }

int main() {
  int h, w, d;
  cin >> h >> w >> d;
  vector<vi> a(h, vi(w));
  rep(i, h) rep(j, w) {
    cin >> a[i][j];
    a[i][j]--;
  }
  vector<vpii> b(d, vpii(h * w / d + 1));
  rep(i, h) rep(j, w) b[(a[i][j]) % d][(a[i][j]) / d] = {i, j};
  vector<vll> sum(d, vll(h * w / d + 1));
  rep(i, d) rep1(j, sz(b[i]) - 1) {
    if (d * j + i >= h * w)
      continue;
    int cost = abs(b[i][j].first - b[i][j - 1].first) +
               abs(b[i][j].second - b[i][j - 1].second);
    sum[i][j] = sum[i][j - 1] + cost;
  }
  int q;
  cin >> q;
  rep(i, q) {
    int l, r;
    cin >> l >> r;
    --l;
    --r;
    ll ans = sum[l % d][r / d] - sum[l % d][l / d];
    cout << ans << endl;
  }
  return 0;
}