結果
| 問題 | 
                            No.699 ペアでチームを作ろう2
                             | 
                    
| ユーザー | 
                             | 
                    
| 提出日時 | 2023-03-06 14:36:53 | 
| 言語 | C++17  (gcc 13.3.0 + boost 1.87.0)  | 
                    
| 結果 | 
                             
                                AC
                                 
                             
                            
                         | 
                    
| 実行時間 | 7 ms / 1,000 ms | 
| コード長 | 5,116 bytes | 
| コンパイル時間 | 4,045 ms | 
| コンパイル使用メモリ | 251,704 KB | 
| 最終ジャッジ日時 | 2025-02-11 05:44:01 | 
| 
                            ジャッジサーバーID (参考情報)  | 
                        judge2 / judge6 | 
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| ファイルパターン | 結果 | 
|---|---|
| sample | AC * 3 | 
| other | AC * 12 | 
ソースコード
#pragma region Macros
// #pragma GCC target("avx,avx2,fma")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("avx,avx2,fma,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
#include <bits/extc++.h>
// #include <bits/stdc++.h>
using namespace std;
using namespace __gnu_pbds;
// using namespace __gnu_cxx;
// #include <atcoder/fenwicktree>
// #include <atcoder/segtree>
// #include <atcoder/maxflow>
// #include <atcoder/all>
// using namespace atcoder;
// #include <boost/multiprecision/cpp_int.hpp>
// namespace mp = boost::multiprecision;
// using Bint = mp::cpp_int;
#define TO_STRING(var) # var
#define pb emplace_back
#define int ll
#define endl '\n'
using ll = long long;
using ld = long double;
const ld PI = acos(-1);
const ld EPS = 1e-10;
const ll INFL = 1LL << 61;
// const int MOD = 998244353;
const int MOD = 1000000007;
__attribute__((constructor))
void constructor() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
}
class UnionFind {
public:
	UnionFind() = default;
    UnionFind(int n) : par(n), 
	    sz(n, 1) { iota(par.begin(), par.end(), 0); }
	int root(int x) {
		if (par[x] == x) return x;
		return (par[x] = root(par[x]));
	}
	bool unite(int x, int y) {
		int rx = root(x);
		int ry = root(y);
        if (rx == ry) return false;
		if (sz[rx] < sz[ry]) swap(rx, ry); // union by size 
		sz[rx] += sz[ry];
		par[ry] = rx;
        return true;
	}
	bool issame(int x, int y) {
		return (root(x) == root(y));
	}
	int size(int x) {
		return sz[root(x)];
	}
    vector<vector<int>> groups(int n) {
        vector<vector<int>> G(n);
        for (int x = 0; x < n; x++) {
            G[root(x)].push_back(x);
        }
		G.erase(
            remove_if(G.begin(), G.end(),
                [&](const vector<int>& v) { return v.empty(); }),
                    G.end());
        return G;
    }
private:
	vector<int> par;
	vector<int> sz;
};
template<int mod> class modint{
public:
    int val = 0;
    modint(int x = 0) { while (x < 0) x += mod; val = x % mod; }
    modint(const modint &r) { val = r.val; } // コピーコンストラクタ
    modint operator -(){ return modint(-val); } // 単項
    modint operator +(const modint &r) { return modint(*this) += r; }
    modint operator -(const modint &r) { return modint(*this) -= r; }
    modint operator *(const modint &r) { return modint(*this) *= r; }
    modint operator /(const modint &r) { return modint(*this) /= r; }
    modint &operator +=(const modint &r) {
        val += r.val;
        if (val >= mod) val -= mod;
        return *this;
    }
    modint &operator -=(const modint &r) {
        if (val < r.val) val += mod;
        val -= r.val;
        return *this;
    }
    modint &operator *=(const modint &r) {
        val = val * r.val % mod;
        return *this;
    }
    modint &operator /=(const modint &r) {
        int a = r.val, b = mod, u = 1, v = 0;
        while (b) {
            int t = a / b;
            a -= t * b; swap(a, b);
            u -= t * v; swap(u, v);
        }
        val = val * u % mod;
        if (val < 0) val += mod;
        return *this;
    }
    bool operator ==(const modint& r) { return this -> val == r.val; }
    bool operator <(const modint& r) { return this -> val < r.val; }
    bool operator !=(const modint& r) { return this -> val != r.val; }
};
using mint = modint<MOD>;
istream &operator >>(istream &is, mint& x) {
    int t; is >> t;
    x = t;
    return (is);
}
ostream &operator <<(ostream &os, const mint& x) {
    return os << x.val;
}
mint modpow(const mint &a, int n) {
    if (n == 0) return 1;
    mint t = modpow(a, n / 2);
    t = t * t;
    if (n & 1) t = t * a;
    return t;
}
int modpow(int x, int N, int mod) {
    int ret = 1;
    while (N > 0) {
        if (N % 2 == 1) ret = ret * x % mod;
        x = x * x % mod;
        N /= 2;
    }
    return ret;
}
int ceil(int x, int y) { return (x > 0 ? (x + y - 1) / y : x / y); }
#pragma endregion
int N;
vector<int> ctz;
bool next_matching(vector<int> &P) {
    int used = 0;
    int used_max = 0;
    for (int i = N - 1; i >= 0; i--) {
        used |= (1 << P[i]);
        used_max = max(used_max, P[i]);
        if (i % 2 == 1 && P[i] < used_max) {
            P[i] = __builtin_ctzll((used >> (P[i] + 1))) + P[i] + 1;
            
            used ^= (1 << P[i]);
            for (int j = i + 1; j < N; j++) {
                P[j] = __builtin_ctzll(used);
                used ^= (1 << P[j]);
            }
            return true;
        }
    }
    return false;
}
signed main() {
    cin >> N;
    vector<int> A(N);
    for (int i = 0; i < N; i++) cin >> A[i];
    vector<int> P(N);
    for (int i = 0; i < N; i++) P[i] = i;
    int ans = 0;
    do {
        int sum = 0;
        int cur = 0;
        for (int i = 0; i < N; i++) {
            if (i % 2 == 0) {
                cur = A[P[i]];
            } else {
                cur += A[P[i]];
                sum ^= cur;
            }
        }
        ans = max(ans, sum);
    } while (next_matching(P));
    cout << ans << endl;
}