Submission #579852

#	Time	Username	Problem	Language	Result	Execution time	Memory
579852		dxz05	Xor Sort (eJOI20_xorsort)	C++14	0 / 100	1 ms	284 KiB

xorsort

#pragma GCC optimize("Ofast,O2,O3,unroll-loops")
#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define lla(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

#define MP make_pair

typedef long long ll;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const double eps = 0.000001;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 1e6 + 3e2;
const int M = 1111;

int a[N];

vector<pair<int, int>> ans;

void add(int i, int j){
    ans.emplace_back(i, j);
    a[i] ^= a[j];
}

void solve(int TC) {
    int n, S;
    cin >> n >> S;

    for (int i = 1; i <= n; i++) cin >> a[i];

    for (int it = 1; it <= n; it++){
        for (int i = n - 1; i >= 1; i--){
            if (a[i] < a[i + 1]) continue;
            int x = a[i] ^ a[i + 1];
            if (x > a[i]){
                add(i + 1, i);
            } else if (a[i + 1] > x){
                add(i, i + 1);
            } else { // a[i] > x > a[i + 1]
                add(i + 1, i);
                add(i, i + 1);
                add(i + 1, i);
            }
        }
    }

//    for (int i = 1; i <= n; i++) cout << a[i] << ' '; cout << endl;

    cout << ans.size() << endl;
    for (auto now : ans) cout << now.first << ' ' << now.second << endl;

}

int main() {
    startTime = clock();
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int TC = 1;
//    cin >> TC;

    for (int test = 1; test <= TC; test++) {
        //debug(test);
        //cout << "Case #" << test << ": ";
        solve(test);
    }

#ifdef dddxxz
    cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;
#endif

    return 0;
}

• Subtask 1: 0 / 25
• Subtask 2: 0 / 35
• Subtask 3: 0 / 40