Submission #970436

#	Time	Username	Problem	Language	Result	Execution time	Memory
970436		steveonalex	Permutation (APIO22_perm)	C++17	91.33 / 100	1 ms	600 KiB

perm

#include <bits/stdc++.h>
#include "perm.h"
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define ALL(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
 
// mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng(1);
ll rngesus(ll l, ll r){return ((ull) rng()) % (r - l + 1) + l;}
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return mask & (-mask);}
ll pop_cnt(ll mask){return __builtin_popcountll(mask);}
ll ctz(ll mask){return __builtin_ctzll(mask);}
ll clz(ll mask){return __builtin_clzll(mask);}
ll logOf(ll mask){return 63 - clz(mask);}
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b){a = b; return true;}
        return false;
    }
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b){a = b; return true;}
        return false;
    }
template <class T>
    void printArr(T& a, string separator = " ", string finish = "\n", ostream& out = cout){
        for(auto i: a) out << i << separator;
        out << finish;
    }
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

vector<int> construct_permutation(ll k){
    k--;
    int j = 0;
    for(; k >= MASK(j + 1) - 1; ++j) ;
    j--;     
    k -= MASK(j+1) - 1;   
    vector<int> ans;
    for(int i = 0; i<=j; ++i) ans.push_back(i);

    for(int i = j; i>=0; --i){
        if (k >= MASK(i)){
            for(int t = i; t < ans.size(); ++t) ans[t]++;
            ans.push_back(i);
            k -= MASK(i);
        }
    }

    return ans;
}

ll count_i(vector<int> perm){
    int n = perm.size();
    perm.insert(perm.begin(), -1);
    vector<ll> dp(n+1); dp[0] = 1;
    ll sum = 1;
    for(int i = 1; i<=n; ++i){
        for(int j = 0; j<i; ++j) if (perm[j] < perm[i]) dp[i] += dp[j];
        sum += dp[i];
    }
    return sum;
}

// int main(void){
//     ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

//     for(int i = 2; i<=100; ++i){
//         vector<int> perm = construct_permutation(i);
//         if (count_i(perm) != i){
//             cout << i << " " << count_i(perm) << "\n";
//             printArr(perm);
//             break;
//         }
//     }

//     return 0;
// }

Compilation message (stderr)

perm.cpp: In function 'std::vector<int> construct_permutation(ll)':
perm.cpp:58:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |             for(int t = i; t < ans.size(); ++t) ans[t]++;
      |                            ~~^~~~~~~~~~~~

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