Submission #1011735

#	Time	Username	Problem	Language	Result	Execution time	Memory
1011735		dimashhh	Permutation (APIO22_perm)	C++17	93.67 / 100	777 ms	600 KiB

perm

#include "perm.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

ll dp[150];
ll K;
ll calc(vector<int> x){
	ll S = 1;
	for(int i = 0;i < (int)x.size();i++){
		dp[i] = 1;
		for(int j = i - 1;j >= 0;j--){
			if(x[j] < x[i]){
				dp[i] += dp[j];
				if(dp[i] > K) return K + 1;
			}
		}
		S += dp[i];
		if(S > K) return K + 1;
	}
	return S;
}
vector<int> ins(vector<int> &x,int a){
	vector<int> ret = x;
	for(int i = 0;i < (int)ret.size();i++){
		if(ret[i] >= a){
			ret[i]++;
		}
	}
	ret.push_back(a);
	return ret;
}
vector<int> solve(ll k,ll G,vector<int> a){
	ll it = 3;
	while(G * it <= k){
		G *= it;
		int m = (int)a.size();
		for(int j = m + it - 2;j >= m;j--){
			a.push_back(j);
		}
	}
	while(G != k){
		ll mx = -1;
		int pos;
		for(int i = 0;i <= (int)a.size();i++){
			ll val = calc(ins(a,i));	
			if(val <= k){
				if(val > mx){
					mx = val;
					pos = i;
				}
			}
		}
		G = mx;
		a = ins(a,pos);
	}
	return a;
}
vector<int> construct_permutation(long long k)
{
	K = k;
	vector<int> ret;
	if(k == 1) return ret;
	auto upd = [&](vector<int> f){
		if(ret.empty() || (int)ret.size() > (int)f.size()){
			ret = f;
		}
	};
	upd(solve(k,1ll,vector<int>()));
	// upd(solve(k,3,{1,0}));
	// upd(solve(k,8,{0,1}));
	return ret;
}

Compilation message (stderr)

perm.cpp: In function 'std::vector<int> solve(ll, ll, std::vector<int>)':
perm.cpp:56:16: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
   56 |   a = ins(a,pos);
      |                ^

• Subtask 1: 10 / 10
• Subtask 2: 83.66666666399999 / 90