Submission #579955

#	Time	Username	Problem	Language	Result	Execution time	Memory
579955		JooDdae	Permutation (APIO22_perm)	C++17	100 / 100	2 ms	340 KiB

perm

#include "perm.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

const int M = 1'000'000, m = 1'000;

vector<int> solve(ll k){
    vector<int> re;

    ll b = 0;
    while((1ll << b) <= k) k -= (1ll << b), re.push_back(++b + M);

    ll r = 0;
    for(int i=b-1;i>=0;i--) r += ((!!(k & (1ll << i))) * 1ll) << (b-1-i);

    int c = 0, L = 0, L2 = 0;
    for(int i=b-1;i>=0;i--, r >>= 1){
        if(!(r & 1)) continue;
        auto it = re.begin() + (b-i) + c;
        if(++c <= 2 || (r & 3) != 3) re.insert(it, M-c*m), L2 = L, L = M-c*m;
        else re.insert(it+1, L2+m-c), r ^= 2;
    }

    return re;
}

vector<int> construct_permutation(ll k)
{
    vector<int> ans = solve(--k);
    vector<int> v = ans; sort(v.begin(), v.end());
    for(auto &x : ans) x = lower_bound(v.begin(), v.end(), x) - v.begin();
    return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 90 / 90