Submission #666511

#	Time	Username	Problem	Language	Result	Execution time	Memory
666511		mychecksedad	Boarding Passes (BOI22_passes)	C++17	5 / 100	405 ms	1856 KiB

passes

/* Author : Mychecksdead */
#include<bits/stdc++.h>
using namespace std;
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
const int N = 1e5 + 100;

int n;
string s;
double dp[N];
vector<int> v[15], pref, vis;

double calc(vector<int> p){
    pref.clear(); pref.resize(n);
    vis.clear(); vis.resize(n);

    double S = 0;

    for(int i = 0; i < p.size(); ++i){

        long long a = v[p[i]].size();

        double best = -1;

        long long cur = 0;
        int po = n - 1;
        for(int j = a - 1; j >= 0; --j){
            int pos = v[p[i]][j];
            cur += pref[n - 1] - pref[pos];
        }

        best = cur + a*(a-1)/4.0;

        for(double k = 1; k <= a; k += 1){

            int pos = v[p[i]][k - 1];

            cur -= pref[n - 1] - pref[pos];

            cur += pref[pos];

            double k1 = a - k;

            double val = (k*(k-1) + k1*(k1-1))/4.0 + cur;

            best = (best == -1 ? val : min(val, best));
        }

        for(int pos: v[p[i]]) vis[pos] = 1;

        for(int j = 0; j < n; ++j){
            if(j == 0) pref[j] = vis[j];
            else pref[j] = pref[j - 1] + vis[j];
        }

        S += best;
    }
    return S;
}

void solve(){
    cin >> s; n = s.length();

    for(int i = 0; i < n; ++i) v[s[i]-'A'].push_back(i);

    vector<int> p;
    
    double ans = 0;

    for(int i = 0; i < 15; ++i){
        double best = -1;
        int pos = 0;
        
        for(int j = 0; j <= i; ++j){
            p.insert(p.begin() + j, i);

            double ans = calc(p);

            if(best == -1 || best > ans) best = ans, pos = j;

            p.erase(p.begin() + j);
        }
        
        ans = best;

        p.insert(p.begin() + pos, i);
    }

    cout << ans;

}



int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    int T = 1, aa;
    // cin >> T;aa=T;
    setp();
    while(T--){
        // cout << "Case #" << aa-T << ": ";
        solve();
    }
    return 0;
 
}

Compilation message (stderr)

passes.cpp: In function 'double calc(std::vector<int>)':
passes.cpp:19:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |     for(int i = 0; i < p.size(); ++i){
      |                    ~~^~~~~~~~~~
passes.cpp:26:13: warning: unused variable 'po' [-Wunused-variable]
   26 |         int po = n - 1;
      |             ^~
passes.cpp: In function 'int main()':
passes.cpp:97:16: warning: unused variable 'aa' [-Wunused-variable]
   97 |     int T = 1, aa;
      |                ^~

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