Submission #625986

#	Time	Username	Problem	Language	Result	Execution time	Memory
625986		berr	Diversity (CEOI21_diversity)	C++17	4 / 100	21 ms	3292 KiB

diversity

#include <bits/stdc++.h>
using namespace std;
vector<int> p(3005);
map<int, int> freq;

int val(int a, int b, int c)
{
   return a*c*(a+(c-1)*b)+b*b*((((c-1)*c*(2*c-1))/6));
}


int get()
{
    int n=0, k=0;
    for(auto [i, l]: freq)
    {
        n+=i*l;
        k+=l;
    }

    int mod=1;

    int l=0, r=0, ans=0;

    for(auto [i, j]: freq)
    {
        if(j<=0) continue;

        int addleft=(j+mod)/2;
        int addright=j-addleft;

        ans+=val(l, i, addleft);
        ans+=val(n-l-i, -i, addleft);

        ans+=val(r, i, addright);
        ans+=val(n-r-i, -i, addright);

        l+=addleft*i;
        r+=addright*i;
        mod=(j+mod)%2;
    }
    return (k*n*(n+1)-n*(k-1)-ans)/2;
}


int32_t main()
{
    ios_base::sync_with_stdio(false); cin.tie(0);
    
    int n, q, b=200, cnt=0; cin>>n>>q;

    vector<int> a(n), ans(q);
    vector<array<int, 3>> query[n/b+1], s;


    for(int i=0; i<n; i++) cin>>a[i];

    while(q--)
    {
        int l, r; cin>>l>>r;
        l--; r--;

        query[l/b].push_back({l, r, ++cnt});
    }


    int l=0, r=-1;

    vector<int> count(300005);


    for(int i=0; i<n/b+1; i++)
    {
        sort(query[i].begin(), query[i].end());
        for(auto x: query[i])
        {
            while(x[0]>l)
            {
                if(count[a[l]]!=0)
                count[a[l]]--;
                freq[count[a[l]]]++;
                freq[count[a[l]]+1]--;
                l++;
            }
            while(x[0]<l)
            {
                l--;
                count[a[l]]++;
                freq[count[a[l]]]--;
                if(freq[count[a[l]]-1]>0)
                freq[count[a[l]]-1]--;
            }
            while(x[1]<r)
            {
                if(count[a[r]]!=0)
               freq[count[a[r]]]--;
               count[a[r]]--;

               freq[count[a[r]]]++;
               r--;
            }

            while(x[1]>r)
            {
                r++;
                if(count[a[r]]!=0)
                freq[count[a[r]]]--;
                count[a[r]]++;
                freq[count[a[r]]]++;
            }

            ans[x[2]-1]=get();
        }
    }

    

    for(int i=0; i<ans.size(); i++) cout<<ans[i]<<"\n";

}

Compilation message (stderr)

diversity.cpp: In function 'int32_t main()':
diversity.cpp:118:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  118 |     for(int i=0; i<ans.size(); i++) cout<<ans[i]<<"\n";
      |                  ~^~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 0 / 10
• Subtask 3: 0 / 8
• Subtask 4: 0 / 16
• Subtask 5: 0 / 26
• Subtask 6: 0 / 36