/// - Art - #include <bits/stdc++.h> #define el cout << '\n' #define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i) #define REV(i, b, a) for (int i = (b), _a = (a); i >= _a; --i) #define REP(i, c) for (int i = 0, _c = (c); i < _c; ++i) const int N = 1e5 + 7; using namespace std; int B, n, D, M; namespace B_1 { bool checkSubtask() { return B == 1; } int point[N]; void solve() { FOR (i, 1, n) { cin >> point[i]; } sort(point + 1, point + n + 1); int it = 1; long long res = 0; FOR (i, 1, n) { while (it <= n && point[it] - point[i] <= D) { ++it; } res += it - i - 1; } cout << res, el; } } struct FenwickTree { int n; vector<int> bit; FenwickTree(int _n = 0) { n = _n; bit.assign(_n + 7, 0); } void update(int u, int add) { for (; u <= n; u += u & -u) { bit[u] += add; } } int get(int u) { int res = 0; for (; u > 0; u -= u & -u) { res += bit[u]; } return res; } int get(int l, int r) { return get(r) - get(l - 1); } }; namespace B_2 { bool checkSubtask() { return B == 2; } pair<int, int> point[N]; void solve() { FOR (i, 1, n) { int x, y; cin >> x >> y; point[i] = {x + y + M, x - y + M}; } sort(point + 1, point + n + 1); FenwickTree fen(2 * M); int it = 1; long long res = 0; FOR (i, 1, n) { while (it <= n && point[it].first - point[i].first <= D) { fen.update(point[it].second, +1); ++it; } fen.update(point[i].second, -1); res += fen.get(point[i].second - D, min(point[i].second + D, 2 * M)); } cout << res, el; } } namespace B_3 { bool checkSubtask() { return B == 3; } vector<pair<int, int>> point[77]; long long countSingle(int idx) { FenwickTree fen(2 * M); int it = 0; long long res = 0; REP (i, point[idx].size()) { while (it < point[idx].size() && point[idx][it].first - point[idx][i].first <= D) { fen.update(point[idx][it].second, +1); ++it; } fen.update(point[idx][i].second, -1); res += fen.get(point[idx][i].second - D, min(point[idx][i].second + D, 2 * M)); } return res; } long long countDouble(int idx_i, int idx_j) { FenwickTree fen(2 * M); int nD = D - abs(idx_j - idx_i); if (nD < 0) { return 0; } int sta = 0, fin = 0; long long res = 0; REP (i, point[idx_i].size()) { while (fin < point[idx_j].size() && /// point_i[i] < point_j[fin] point[idx_j][fin].first - point[idx_i][i].first <= nD) { fen.update(point[idx_j][fin].second, +1); ++fin; } while (sta < fin && /// Lỗi 1: coi i là trung tâm sta, fin là 2 bên của j /// nên ko được phép dùng abs của cả 2 phép trên /// point_i[i] > point_j[sta] point[idx_i][i].first - point[idx_j][sta].first > nD) { fen.update(point[idx_j][sta].second, -1); ++sta; } res += fen.get(point[idx_i][i].second - nD, min(point[idx_i][i].second + nD, 2 * M)); } return res; } void solve() { FOR (i, 1, n) { int x, y, z; cin >> x >> y >> z; point[x].emplace_back(y + z + M, y - z + M); } long long res = 0; FOR (i, 1, M) if (!point[i].empty()) { sort(point[i].begin(), point[i].end()); res += countSingle(i); FOR (j, 1, i - 1) if (!point[j].empty()) { res += countDouble(j, i); } } cout << res, el; } } int main() { #define name "art" if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); } ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> B >> n >> D >> M; if (B_1::checkSubtask()) return B_1::solve(), 0; if (B_2::checkSubtask()) return B_2::solve(), 0; if (B_3::checkSubtask()) return B_3::solve(), 0; return 0; }

pairs.cpp: In function 'int main()':
pairs.cpp:170:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  170 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
pairs.cpp:171:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  171 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~