Submission #514797

#	Time	Username	Problem	Language	Result	Execution time	Memory
514797		Theo830	Cheerleaders (info1cup20_cheerleaders)	C++17	13 / 100	2110 ms	765184 KiB

cheerleaders

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e9+7;
const ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ii,ll>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
template <typename T> struct Bit{
    int N;
    vector<T>bit;
    void build(ll n){
        N = n+5;
        f(i,0,N){
            bit.pb(0);
        }
    }
    void upd(ll k,T x){
        while(k < N){
            bit[k] += x;
            k += k & -k;
        }
    }
    T query(ll k){
        T ans = 0;
        while(k >= 1){
            ans += bit[k];
            k -= k & -k;
        }
        return ans;
    }
};
ll n;
vll arr;
ll c(vll a){
    ll ans = 0;
    Bit<ll>b;
    b.build(a.size() + 5);
    f(j,0,(ll)a.size()){
        ans += j - b.query(a[j]+1);
        b.upd(a[j]+1,1);
    }
    return ans;
}
vll ena(vll a){
    vll ans;
    ll m = a.size() / 2;
    f(i,m,a.size()){
        ans.pb(a[i]);
    }
    f(i,0,m){
        ans.pb(a[i]);
    }
    return ans;
}
vll dio(vll a){
    vll ans;
    f(i,0,a.size()){
        ans.pb(a[i]);
        i++;
    }
    f(i,1,a.size()){
        ans.pb(a[i]);
        i++;
    }
    return ans;
}
int main(void){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin>>n;
    n = (1LL<<n);
    f(i,0,n){
        ll a;
        cin>>a;
        arr.pb(a);
    }
    map<vll,bool>v;
    queue<vll>q;
    q.push(arr);
    v[arr] = 1;
    ll ans = 1e18;
    while(!q.empty()){
        vll f = q.front();
        q.pop();
        ans = min(ans,c(f));
        vll A = ena(f);
        if(!v[A]){
            v[A] = 1;
            q.push(A);
        }
        A = dio(f);
        if(!v[A]){
            v[A] = 1;
            q.push(A);
        }
    }
    cout<<ans<<"\n";
}

Compilation message (stderr)

cheerleaders.cpp: In function 'std::vector<long long int> ena(std::vector<long long int>)':
cheerleaders.cpp:8:33: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 | #define f(i,a,b) for(ll i = a;i < b;i++)
......
   64 |     f(i,m,a.size()){
      |       ~~~~~~~~~~~~               
cheerleaders.cpp:64:5: note: in expansion of macro 'f'
   64 |     f(i,m,a.size()){
      |     ^
cheerleaders.cpp: In function 'std::vector<long long int> dio(std::vector<long long int>)':
cheerleaders.cpp:8:33: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 | #define f(i,a,b) for(ll i = a;i < b;i++)
......
   74 |     f(i,0,a.size()){
      |       ~~~~~~~~~~~~               
cheerleaders.cpp:74:5: note: in expansion of macro 'f'
   74 |     f(i,0,a.size()){
      |     ^
cheerleaders.cpp:8:33: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 | #define f(i,a,b) for(ll i = a;i < b;i++)
......
   78 |     f(i,1,a.size()){
      |       ~~~~~~~~~~~~               
cheerleaders.cpp:78:5: note: in expansion of macro 'f'
   78 |     f(i,1,a.size()){
      |     ^

• Subtask 1: 8 / 16
• Subtask 2: 5 / 10
• Subtask 3: 0 / 25
• Subtask 4: 0 / 21
• Subtask 5: 0 / 28