Submission #1122051

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122051		vjudge1	Boarding Passes (BOI22_passes)	C++14	60 / 100	2065 ms	7236 KiB

passes

// Bolatulu
#include <bits/stdc++.h>
// #include <art.h>

/*
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
*/

typedef long long ll;
typedef unsigned long long ull; 
typedef double db;
#define pb push_back
#define eb emplace_back
#define ins insert
#define F first
#define S second
#define md (tl+tr)/2
#define TL v+v,tl,md
#define TR v+v+1,md+1,tr
#define Tl t[v].l,tl,md
#define Tr t[v].r,md+1,tr
#define all(x) (x).begin(),(x).end()
#define yes cout << "YES\n"
#define no cout << "NO\n"
#define int long long
// #define file(s) freopen(s".in", "r", stdin); freopen(s".out", "w", stdout);
using namespace std;

int binpow(int a,int n,int M) {
    if (n==0)
        return 1;
    if (n%2!=0)
        return (a * binpow(a,n-1,M))%M;
    int z=binpow(a,n/2,M);
    return (z*z)%M;
}

const ll INF = 1e18+7;
const int N = 2e5+7;

int n,dp[N],a[N],c[N];
string s;
vector <int> d[N];

void solve() {
    cin >> s;
    n=s.size();
    s=" "+s;
    int g=0;
    for (int i=1;i<=n;i++) {
        g=max(g,(int)(s[i]-'A'+1));
        d[s[i]-'A'].pb(i);
    }
    dp[0]=0;
    for (int mask=1;mask<(1<<g);mask++) {
        vector <int> v,bits;
        for (int i=0;i<g;i++) {
            c[i]=0;
            if (mask>>i&1)
                bits.pb(i);
        }
        int x=0;
        for (int i=1;i<=n;i++) {
            int bit=s[i]-'A';
            if (mask>>bit&1) {
                a[i]=x*2-c[bit];
                x++;
                c[bit]++;
            }
        }
        for (auto i : bits)
            c[i]=0;
        x=0;
        for (int i=n;i>=1;i--) {
            int bit=s[i]-'A';
            if (mask>>bit&1) {
                a[i]=min(a[i],x*2-c[bit]);
                x++;
                c[bit]++;
            }
        }
        for (auto i : bits)
            c[i]=0;
        for (int i=1;i<=n;i++) {
            int bit=s[i]-'A';
            if (mask>>bit&1)
                c[bit]+=a[i];
        }
        dp[mask]=INF;
        for (auto i : bits)
            dp[mask]=min(dp[mask^(1<<i)]+c[i],dp[mask]);
    }
    int ans=dp[(1<<g)-1];
    if (ans%2!=0)
        cout << ans/2 << ".5";
    else
        cout << ans/2;
}   

signed main() {
    // file("jenga");
    ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
    int test = 1;
    // cin >> test;
    while (test--) {
        solve();
        if (test)
            cout << '\n';
    }
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 25 / 25
• Subtask 3: 30 / 30
• Subtask 4: 0 / 40