Submission #645649

#	Time	Username	Problem	Language	Result	Execution time	Memory
645649		czhang2718	Permutation (APIO22_perm)	C++17	91.33 / 100	3 ms	340 KiB

perm

#include "bits/stdc++.h"
using namespace std;
 
// #include "perm.h"
 
std::vector<int> construct_permutation(long long S)
{
    vector<int> v;
    bool emp=1;
    for(int i=30; i>=0; i--){
        int d=(S/(1LL<<(2*i)))%4;
        if(emp){
            if(!d) continue;
            if(d==1) {}
            if(d==2) v={0};
            if(d==3) v={1,0};
            emp=0;
            continue;
        }
        if(d==0){
            int mx=(v.size()?*max_element(v.begin(), v.end()):0);
            v.push_back(mx+1);
            v.push_back(mx+2);
        }
        if(d==1){
            int mx=(v.size()?*max_element(v.begin(), v.end()):0);
            v.push_back(mx+1);
            v.push_back(mx+2);
            int mn=(v.size()?*min_element(v.begin(), v.end()):0);
            v.push_back(mn-1);
        }
        if(d==2){
            int mx=(v.size()?*max_element(v.begin(), v.end()):0);
            v.push_back(mx+1);
            int mn=(v.size()?*min_element(v.begin(), v.end()):0);
            v.push_back(mn-1);
            v.push_back(mx+2);
        }
        if(d==3){
            int mx=(v.size()?*max_element(v.begin(), v.end()):0);
            v.push_back(mx+1);
            v.push_back(mx+2);
            int mn=(v.size()?*min_element(v.begin(), v.end()):0);
            int i0=-1,i1=-1;
            for(int j=0; j<v.size(); j++){
                if(v[j]==mn) i0=j;
                if(v[j]==mn+1) i1=j;
            }
            if(i1!=-1 && i0!=-1 && i1<i0){
                v[i0]--, v[i1]--;
                v.push_back(mn+1);
            }
            else{
                v.push_back(mn-2);
                v.push_back(mn-1);
            }
        }
    }
    vector<int> a=v;
    sort(a.begin(), a.end());
    for(int &x:v) x=lower_bound(a.begin(), a.end(), x)-a.begin();
    return v;
}
 
 
// int main(){
//     cin.tie(0)->sync_with_stdio(0);
 
//     int k; cin >> k;
//     for(int x:construct_permutation(k)) cout << x << " ";
// }

Compilation message (stderr)

perm.cpp: In function 'std::vector<int> construct_permutation(long long int)':
perm.cpp:45:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |             for(int j=0; j<v.size(); j++){
      |                          ~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 81.333333333 / 90