Submission #581167

#	Time	Username	Problem	Language	Result	Execution time	Memory
581167		wdjpng	Boarding Passes (BOI22_passes)	C++17	25 / 100	2081 ms	1484 KiB

passes

#include <bits/stdc++.h>

#define int long long
#define double long double
#define rep(i,n) for(int i =0; i<n; i++)
#define all(a) a.begin(),a.end()

using namespace std;


string s;
int n;
double f(int n)
{
    return ((double)  n)*((double) (n-1))/4.0;
}

string ord;
vector<double>mem;
vector<vector<int>>pos;
int g;
// cost to add the group gr with all members of that group with and index <= to maxi boarding on the left
double cost(int bor, int gr, int firstr)
{
    double sum = 0;

    sum+=f(pos[gr].size()-firstr) + f(firstr);


    vector<int>otherpos;
    rep(i,n) if(((1<<(s[i]-'A'))&bor)==0) otherpos.push_back(i);

    rep(i,firstr)
    {
        sum+=upper_bound(all(otherpos),pos[gr][i])-otherpos.begin();
    }

    for(int i = firstr; i < pos[gr].size(); i++) sum+=otherpos.end()-upper_bound(all(otherpos),pos[gr][i]);

    return sum;
}

vector<int>lookup;
double dfs(int bor)
{
    if(mem[bor]>-0.9) return mem[bor];


    double sol = 1e18;
    rep(i,g)
    {
        if(!((1<<i)&bor)) continue;
        int nbor = bor^(1<<i);
        if(!pos[i].size()) return mem[bor]=dfs(nbor);
        int start = -1, end = pos[i].size();
        while(end-start>1)
        {
            int c = (start+end)/2;
            double l =cost(bor,i,c), r=cost(bor,i,c+1);
    
            if(r>=l) end=c;
            else start=c;
        };
        
        sol=min(sol, cost(bor,i,end)+dfs(nbor));

        vector<int>otherpos;
        rep(j,n) if(((1<<(s[j]-'A'))&bor)==0) otherpos.push_back(j);

        double sol1=1e18;
        rep(firstr,pos[i].size()+1)
        {
            double sum2 = f(pos[i].size()-firstr) + f(firstr);
            rep(j,firstr) sum2+=upper_bound(all(otherpos),pos[i][j])-otherpos.begin();
            for(int j = firstr; j < pos[i].size(); j++) sum2+=otherpos.end()-upper_bound(all(otherpos),pos[i][j]);
            sol1=min(sol1,sum2+dfs(nbor));
        }
        double csol=cost(bor,i,end)+dfs(nbor);
        assert(csol==sol1);
    }
    return mem[bor] = sol;
}


signed main()
{
    cin>>s;
    s.size();
    n=s.size();

    cout.precision(300);
    
    char maxx=0;
    rep(i,n) maxx=max(maxx, s[i]);
    g=maxx-'A'+1;

    pos.resize(g);
   

    rep(i,n) pos[(s[i]-'A')].push_back(i);
    lookup.assign(g,0);
    rep(i,g) lookup[i]=i;
    mem.assign(1<<g,-1.0);
    mem[0]=0;
    cout<<dfs((1<<g)-1)<<'\n';
}

Compilation message (stderr)

passes.cpp: In function 'long double cost(long long int, long long int, long long int)':
passes.cpp:38:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |     for(int i = firstr; i < pos[gr].size(); i++) sum+=otherpos.end()-upper_bound(all(otherpos),pos[gr][i]);
      |                         ~~^~~~~~~~~~~~~~~~
passes.cpp: In function 'long double dfs(long long int)':
passes.cpp:5:33: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    5 | #define rep(i,n) for(int i =0; i<n; i++)
......
   71 |         rep(firstr,pos[i].size()+1)
      |             ~~~~~~~~~~~~~~~~~~~~~~
passes.cpp:71:9: note: in expansion of macro 'rep'
   71 |         rep(firstr,pos[i].size()+1)
      |         ^~~
passes.cpp:75:35: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |             for(int j = firstr; j < pos[i].size(); j++) sum2+=otherpos.end()-upper_bound(all(otherpos),pos[i][j]);
      |                                 ~~^~~~~~~~~~~~~~~

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