結果
| 問題 | 
                            No.2517 Right Triangles on Circle
                             | 
                    
| コンテスト | |
| ユーザー | 
                             | 
                    
| 提出日時 | 2023-10-27 22:12:28 | 
| 言語 | C++17  (gcc 13.3.0 + boost 1.87.0)  | 
                    
| 結果 | 
                             
                                AC
                                 
                             
                            
                         | 
                    
| 実行時間 | 153 ms / 2,000 ms | 
| コード長 | 4,673 bytes | 
| コンパイル時間 | 1,882 ms | 
| コンパイル使用メモリ | 204,456 KB | 
| 最終ジャッジ日時 | 2025-02-17 15:09:24 | 
| 
                            ジャッジサーバーID (参考情報)  | 
                        judge5 / judge4 | 
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| ファイルパターン | 結果 | 
|---|---|
| sample | AC * 3 | 
| other | AC * 29 | 
ソースコード
#line 1 "combined.cpp"
#pragma region Macros
#include <bits/stdc++.h>
using namespace std;
template <class T> inline bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T> inline bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return 1;
    }
    return 0;
}
#ifdef DEBUG
template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    os << '(' << p.first << ',' << p.second << ')';
    return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
    os << '{';
    for(int i = 0; i < (int)v.size(); i++) {
        if(i) { os << ','; }
        os << v[i];
    }
    os << '}';
    return os;
}
void debugg() { cerr << endl; }
template <class T, class... Args>
void debugg(const T &x, const Args &... args) {
    cerr << " " << x;
    debugg(args...);
}
#define debug(...)                                                             \
    cerr << __LINE__ << " [" << #__VA_ARGS__ << "]: ", debugg(__VA_ARGS__)
#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif
struct Setup {
    Setup() {
        cin.tie(0);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(15);
    }
} __Setup;
using ll = long long;
#define OVERLOAD3(_1, _2, _3, name, ...) name
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define REP1(i, n) for(int i = 0; i < int(n); i++)
#define REP2(i, a, b) for(int i = (a); i < int(b); i++)
#define REP(...) OVERLOAD3(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)
#define UNIQUE(v) sort(ALL(v)), (v).erase(unique(ALL(v)), (v).end())
#define REVERSE(v) reverse(ALL(v))
#define SZ(v) ((int)(v).size())
const int INF = 1 << 30;
const ll LLINF = 1LL << 60;
constexpr int MOD = 1000000007;
constexpr int MOD2 = 998244353;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
void Case(int i) { cout << "Case #" << i << ": "; }
int popcount(int x) { return __builtin_popcount(x); }
ll popcount(ll x) { return __builtin_popcountll(x); }
#pragma endregion Macros
#line 2 "/Users/siro53/kyo-pro/compro_library/misc/compress.hpp"
#line 5 "/Users/siro53/kyo-pro/compro_library/misc/compress.hpp"
template <typename T> class Compress {
  public:
    Compress() = default;
    explicit Compress(const std::vector<T> &v) : dat(v) {
        build();
    }
    void push_back(T val) { dat.push_back(val); }
	void build() {
		std::sort(dat.begin(), dat.end());
        dat.erase(std::unique(dat.begin(), dat.end()), dat.end());
	}
    int get(T val) const {
        int pos = std::lower_bound(dat.begin(), dat.end(), val) - dat.begin();
        return pos;
    }
    T operator[](int i) const { return dat[i]; }
    size_t size() const { return dat.size(); }
  private:
    std::vector<T> dat;
};
#line 2 "/Users/siro53/kyo-pro/compro_library/data-structure/BIT.hpp"
#line 5 "/Users/siro53/kyo-pro/compro_library/data-structure/BIT.hpp"
template <typename T> class BIT {
  public:
    BIT() = default;
    explicit BIT(int N) : N(N), dat(N + 1, 0) {}
    T sum(int r) {
        T ret = 0;
        for(; r >= 1; r -= lsb(r)) ret += dat[r];
        return ret;
    }
    T sum(int l, int r) {
        assert(l <= r);
        if(l == r) return T(0);
        return (sum(r) - sum(l));
    }
    void add(int pos, T val) {
        for(int i = pos + 1; i <= N; i += lsb(i)) dat[i] += val;
    }
    int lower_bound(T val) {
        int pos = 0;
        int k = 1;
        while(2 * k <= N) k <<= 1;
        for(; k >= 1; k >>= 1) {
            if(pos + k <= N and dat[pos + k] < val) {
                pos += k;
                val -= dat[pos];
            }
        }
        return pos + 1;
    }
  private:
    int N;
    std::vector<T> dat;
    inline int lsb(int i) { return i & (-i); }
};
#line 79 "combined.cpp"
void solve() {
    int N; ll M;
    cin >> N >> M;
    vector<ll> A(N);
    Compress<ll> comp;
    REP(i, N) {
        cin >> A[i];
        comp.push_back((A[i] * 2) % (M * 2));
    }
    comp.build();
    int sz = SZ(comp);
    vector<int> rev(sz);
    REP(i, N) rev[comp.get((A[i] * 2) % (M * 2))] = i;
    BIT<int> bt(N);
    ll ans = 0;
    REP(i, N) {
        int p = comp.get((A[i] * 2 + M) % (M * 2));
        if(comp[p] != (A[i] * 2 + M) % (M * 2)) {
            // bt.add(i, 1);
            continue;
        }
        int l = rev[p], r = i;
        if(l > r) {
            // bt.add(i, 1);
            continue;
        }
        ans += N-2;
        bt.add(i, 1);
    }
    cout << ans << endl;
}
int main() {
    int T{1};
    // cin >> T;
    while(T--) solve();
}