Submission #896885

#	Time	Username	Problem	Language	Result	Execution time	Memory
896885		Litusiano	Permutation (APIO22_perm)	C++17	10 / 100	33 ms	476 KiB

perm

#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector,fast-math,inline")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,lzcnt,mmx,abm,avx,avx2,fma")
#include<bits/stdc++.h>
 #include "perm.h"
using namespace std;

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

vector<int> shuffle(vector<int>& v){
	int sz = v.size();
	for(int i = 0; i < 2 * v.size(); i++){
		int a = rng()%sz; int b = rng()%sz;
		swap(v[a],v[b]);
	}
	return v;
}

long long getdp(vector<int>& v, long long MX) {
  vector<long long> dp(v.size() + 1, 0);
  dp[0] = 1;
  for (int x : v)
  {
  	for (int i = 0; i <= x; i++)
  	{
  		dp[x+1] += dp[i];
  		dp[x+1] = min(dp[x+1],MX+1);
  		if(dp[x+1] == MX+1) return MX+1;
  	}
  }
  long long result = 0;
  for (int i = 0; i <= (int)v.size(); i++){
  	result += dp[i];
  	result = min(result,MX+1);
  }
  return result;
}

vector<int> construct_permutation(long long k)
{
	int z = 0;
	const int CT = 1;
	if(k <= 90){

		vector<int> v; 
		for(int i = k-2; i>=0; i--){
			v.push_back(i);
		}
		return v;
	}
	vector<int> v;
	for(int a = 1; a<=90; a++){
		v.push_back(a-1);
		if(a >= 7){
			z+= CT * a * a;
			for(int _ = 0; _ < CT; _++){
				v = shuffle(v);
				if(getdp(v,k) == k){
					return v;
				}
			}
		}
		else{
			int f = 1;
			for(int i = 1; i<=a; i++) f*=i;
			z+= f * a * a;
			sort(v.begin(),v.end());
			do{
				if(getdp(v,k) == k) return v;
			}while(next_permutation(v.begin(),v.end()));
		}
	}
	// cerr<<z*100ll<<endl;
	return v;
}

Compilation message (stderr)

perm.cpp: In function 'std::vector<int> shuffle(std::vector<int>&)':
perm.cpp:11:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |  for(int i = 0; i < 2 * v.size(); i++){
      |                 ~~^~~~~~~~~~~~~~

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