Submission #873262

#	Time	Username	Problem	Language	Result	Execution time	Memory
873262		salmon	Permutation (APIO22_perm)	C++17	100 / 100	2 ms	508 KiB

perm

#include "perm.h"

#include <bits/stdc++.h>
using namespace std;

vector<int> construct_permutation(long long k){
    if(k <= 90){
        vector<int> v;

        for(int i = 0; i < k - 1; i++){
            v.push_back(i);
        }

        reverse(v.begin(),v.end());

        return v;
    }

    vector<int> v;
    vector<int> temp;
    vector<int> bits;
    bool flag = false;

    while(k != 0){
        bits.push_back(k % 2);
        k /= 2;
    }

    bits.pop_back();

    reverse(bits.begin(),bits.end());

    if(bits[0] == 1){
        flag = true;

        v.push_back(1);
        v.push_back(0);
    }
    else{
        v.push_back(0);
    }

    for(int i = 1; i < bits.size(); i++){
        if(flag){
            if(bits[i] == 1 && i < bits.size() - 1 && bits[i + 1] == 1){
                for(int i = 0; i < v.size(); i++){
                    if(v[i] >= 2){
                        v[i]++;
                    }
                }

                v.push_back(v.size() + 1);
                v.push_back(v.size() + 1);
                v.push_back(2);

                i++;
            }
            else if(bits[i] == 0){
                v.push_back(v.size());
            }
            else{
                temp.clear();

                temp.push_back(v.size() + 1);

                for(int i : v){
                    temp.push_back(i);
                }
                temp.push_back(v.size());

                v = temp;
            }

        }
        else{
            if(bits[i] == 0){
                temp.clear();

                temp.push_back(0);
                for(int i : v){
                    temp.push_back(i + 1);
                }

                v = temp;
            }
            else{
                temp.clear();

                temp.push_back(1);

                for(int i : v){
                    temp.push_back(i + 2);
                }
                temp.push_back(0);

                v = temp;

                flag = true;
            }
        }
    }

    return v;
}

Compilation message (stderr)

perm.cpp: In function 'std::vector<int> construct_permutation(long long int)':
perm.cpp:43:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |     for(int i = 1; i < bits.size(); i++){
      |                    ~~^~~~~~~~~~~~~
perm.cpp:45:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |             if(bits[i] == 1 && i < bits.size() - 1 && bits[i + 1] == 1){
      |                                ~~^~~~~~~~~~~~~~~~~
perm.cpp:46:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |                 for(int i = 0; i < v.size(); i++){
      |                                ~~^~~~~~~~~~

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