Submission #725189

#	Time	Username	Problem	Language	Result	Execution time	Memory
725189		Batorgil952	Permutation (APIO22_perm)	C++17	10 / 100	56 ms	340 KiB

perm

#include<bits/stdc++.h>
#include "perm.h"

using namespace std;

std::vector<int> construct_permutation(long long k)
{
	vector< int > v;
	if(k<=256){
		long long p=2, s=1, r=0;
		while(k>p){
			p*=2;
			s++;
		}
		s--;
		long long a[100], dp[100];
		while(r==0){
			v.clear();
			a[0]=0;
			for(long long i=0; i<s; i++){
				a[i+1]=i;
			}
			long long ind=0;
			do{
				for(long long i=0; i<=s; i++){
					dp[i]=0;
				}
				long long ss=0;
				dp[0]=1;
				for(long long i=1; i<=s; i++){
					for(long long j=0; j<=i-1; j++){
						if(a[j]<=a[i]) dp[i]+=dp[j];
					}
				}
				for(long long i=0; i<=s; i++){
					ss+=dp[i];
				}
				if(ss==k){
					ind++;
					break;
				}
			}while(next_permutation(a+1, a+s+1));
			if(ind==0) s++;
			else{
				r++;
			}
		}
		for(long long i=1; i<=s; i++){
			v.push_back(a[i]);
		}
		return v;
	}
	long long a[62], b[62];
	long long m=k, f=-1, r;
	for(long long i=0; i<=59; i++){
		if(m%2==1){
			a[i]=1;
		}
		m/=2;
	}
	for(long long i=59; i>=0; i--){
		if(a[i]>0){
			if(f==-1){
				f=i;
				r=f;
			}
			else{
				b[i]=f;
				f++;
			}
		}
	}
	for(long long i=0; i<=59; i++){
		if(b[i]>0) v.push_back(b[i]);
		if(i<r) v.push_back(i);
	}
	return v;
}

Compilation message (stderr)

perm.cpp: In function 'std::vector<int> construct_permutation(long long int)':
perm.cpp:75:3: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
   75 |   if(i<r) v.push_back(i);
      |   ^~

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