Problem p03426 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
#define SORT(a) sort(a.begin(), a.end())
#define RSORT(a) sort(a.rbegin(), a.rend())
#define REP(i, n) for (int i = 0; i < n; i++)
#define RREP(i, n) for (int i = n - 1; 0 <= i; i--)
#define FOR(i, start, end) for (int i = start; i < end; i++)
#define RFOR(i, start, end) for (int i = start - 1; 0 <= i; i--)
#define ALL(a) a.begin(), a.end()
using ll = long long;
using namespace std;
const int INF32 = 1'050'000'000;
const long long INF64 = 4'000'000'000'000'000'000;
const int MOD7 = 1'000'000'007;
const int MOD9 = 1'000'000'009;
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
void print() { std::cout << '\n'; }
template <class H, class... T> void print(H &&head, T &&...args) {
  std::cout << head;
  sizeof...(args) == 0 ? std::cout << "" : std::cout << ' ';
  print(std::forward<T>(args)...);
}
template <class T> void print(std::vector<T> &v) {
  for (int i = 0; i < v.size(); i++) {
    std::cout << v[i];
    i == v.size() - 1 ? std::cout << '\n' : std::cout << ' ';
  }
}
template <class T> void print(std::vector<std::vector<T>> &v) {
  for (int i = 0; i < v.size(); i++) {
    for (int j = 0; j < v[i].size(); j++) {
      std::cout << v[i][j];
      j == v[i].size() - 1 ? std::cout << '\n' : std::cout << ' ';
    }
  }
}

template <class T> T mandist(int x1, int y1, int x2, int y2) {
  return abs(x2 - x1) + abs(y2 - y1);
}

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

  int H, W, D;
  cin >> H >> W >> D;
  vector<pair<int, int>> v(H * W + 1);
  REP(i, H) {
    REP(j, W) {
      int x;
      cin >> x;
      v[x] = {i, j};
    }
  }
  vector<ll> cost(H * W + 1);
  REP(i, H * W + 2) {
    if (i <= D)
      continue;
    cost[i] = cost[i - D] + mandist<ll>(v[i].first, v[i].second, v[i - D].first,
                                        v[i - D].second);
  }
  int Q;
  cin >> Q;
  REP(i, Q) {
    int l, r;
    cin >> l >> r;
    print(cost[r] - cost[l]);
  }

  return 0;
}

Fixed submission:
#include <bits/stdc++.h>
#define SORT(a) sort(a.begin(), a.end())
#define RSORT(a) sort(a.rbegin(), a.rend())
#define REP(i, n) for (int i = 0; i < n; i++)
#define RREP(i, n) for (int i = n - 1; 0 <= i; i--)
#define FOR(i, start, end) for (int i = start; i < end; i++)
#define RFOR(i, start, end) for (int i = start - 1; 0 <= i; i--)
#define ALL(a) a.begin(), a.end()
using ll = long long;
using namespace std;
const int INF32 = 1'050'000'000;
const long long INF64 = 4'000'000'000'000'000'000;
const int MOD7 = 1'000'000'007;
const int MOD9 = 1'000'000'009;
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
void print() { std::cout << '\n'; }
template <class H, class... T> void print(H &&head, T &&...args) {
  std::cout << head;
  sizeof...(args) == 0 ? std::cout << "" : std::cout << ' ';
  print(std::forward<T>(args)...);
}
template <class T> void print(std::vector<T> &v) {
  for (int i = 0; i < v.size(); i++) {
    std::cout << v[i];
    i == v.size() - 1 ? std::cout << '\n' : std::cout << ' ';
  }
}
template <class T> void print(std::vector<std::vector<T>> &v) {
  for (int i = 0; i < v.size(); i++) {
    for (int j = 0; j < v[i].size(); j++) {
      std::cout << v[i][j];
      j == v[i].size() - 1 ? std::cout << '\n' : std::cout << ' ';
    }
  }
}

template <class T> T mandist(int x1, int y1, int x2, int y2) {
  return abs(x2 - x1) + abs(y2 - y1);
}

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

  int H, W, D;
  cin >> H >> W >> D;
  vector<pair<int, int>> v(H * W + 1);
  REP(i, H) {
    REP(j, W) {
      int x;
      cin >> x;
      v[x] = {i, j};
    }
  }
  vector<ll> cost(H * W + 1);
  REP(i, H * W + 1) {
    if (i <= D)
      continue;
    cost[i] = cost[i - D] + mandist<ll>(v[i].first, v[i].second, v[i - D].first,
                                        v[i - D].second);
  }
  int Q;
  cin >> Q;
  REP(i, Q) {
    int l, r;
    cin >> l >> r;
    print(cost[r] - cost[l]);
  }

  return 0;
}