Submission #730836

#	Time	Username	Problem	Language	Result	Execution time	Memory
730836		Jarif_Rahman	Permutation (APIO22_perm)	C++17	0 / 100	1 ms	212 KiB

perm

#include "perm.h"
#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

vector<int> construct_permutation(ll k){
    k--;

    vector<int> sth;
    int n = 0;

    int P = 0;
    while((1LL<<P)-1 <= k) P++;
    P--;
    k-=(1LL<<P)-1;
    n+=P;

    vector<int> s(P);
    ll ss = 0;

    vector<int> o;
    for(int i = P-1; i > 0; i--) o.pb(i);
    shuffle(o.begin(), o.end(), rng);

    for(int i = 0; i < o.size(); i++){
        int p = 1;
        while((1LL<<p)-1 + ((1LL<<p)-1)*((1LL<<o[i])-1) <= k) p++;
        p--;
        k-=(1LL<<p)-1 + ((1LL<<p)-1)*((1LL<<o[i])-1);
        s[o[i]] = p;
        n+=p; 
    }

    while(k > 0){
        int p = 0;
        while((1LL<<p)-1 <= k) p++;
        p--;
        k-=(1LL<<p)-1;
        sth.pb(p);
        n+=p;
    }

    vector<int> ans;
    for(int x: sth){
        for(int i = n-x; i < n; i++) ans.pb(i);
        n-=x;
    }

    vector<int> anss, pp;
    for(int i = n-P; i < n; i++) pp.pb(i);
    n-=P;
    if(!pp.empty()) anss.pb(pp[0]);
    for(int i = 1; i < P; i++){
        while(s[P-i]--) anss.pb(n-1), n--;
        anss.pb(pp[i]);
    }

    ans.insert(ans.end(), anss.begin(), anss.end());

    return ans;
}

Compilation message (stderr)

perm.cpp: In function 'std::vector<int> construct_permutation(ll)':
perm.cpp:31:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for(int i = 0; i < o.size(); i++){
      |                    ~~^~~~~~~~~~
perm.cpp:25:8: warning: unused variable 'ss' [-Wunused-variable]
   25 |     ll ss = 0;
      |        ^~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 90