Submission #144028

#	Time	Username	Problem	Language	Result	Execution time	Memory
144028		davitmarg	Arranging Shoes (IOI19_shoes)	C++17	45 / 100	189 ms	12356 KiB

shoes

/*DavitMarg*/
#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <string>
#include <cstring>
#include <map>
#include <set>
#include <queue>
#include <iomanip>
#include <stack>
#include <cassert>
#include <iterator>
#include <bitset>
#include <fstream>
#define mod 1000000007ll
#define LL long long
#define LD long double
#define MP make_pair
#define PB push_back
#define all(v) v.begin(),v.end()
using namespace std;

LL ans,ANS;
int n,id=1,used[200005];
vector<int> a,en[200005];

void mergeSerge(int l,int r)
{
    if(l>=r)
        return;
    int m=(l+r)/2;

    mergeSerge(l,m);
    mergeSerge(m+1,r);
    vector<int> x,y;

    for(int i=l;i<=m;i++)
        x.PB(a[i]);
    for(int i=m+1;i<=r;i++)
        y.PB(a[i]);

    int d=l;
    int p=0,k=0;
    while(p<x.size())
    {
        while(k<y.size() && y[k]<x[p])
        {
            ans+=(LL)(x.size()-p);
            a[d++]=y[k++];
        }
        a[d++]=x[p++];
    }
    while(k<y.size())
        a[d++]=y[k++];

}

LL count_swaps(vector<int> A)
{
    a=A;
    n=A.size()/2;
    for(int i=0;i<a.size();i++)
    {
        if(a[i]>0)
            en[a[i]].PB(i);
    }
    for(int i=1;i<=n;i++)
       reverse(all(en[i]));
    for(int i=0;i<a.size();i++)
        if(!used[i] && a[i]<0)
        {
            used[i]=1;
            //cout<<i<<" - "<<en[-a[i]].back()<<endl;
            a[en[-a[i]].back()]=id+1;
            en[-a[i]].pop_back();
            a[i]=id;
            id+=2;
        }
	A=a;
    //for(int i=0;i<a.size();i++)
    //cout<<a[i]<<":";
    //cout<<endl;

    mergeSerge(0,2*n-1);
	ANS=ans;
	ans=0;
	a=A;
	reverse(all(a));
    for(int i=0;i<a.size();i++)
		a[i]*=-1;
    mergeSerge(0,2*n-1);

	ans=min(ANS,ans);
    return ans;
}

//#define death

#ifdef death

int main()
{
    int N;
    cin>>N;
    N*=2;
    vector<int> X;
    for(int i=0;i<N/2;i++)
    {
		int val=rand()%(N/2)+1;
        X.PB(val);
        X.PB(-val);
        //cin>>X.back();
    }
	random_shuffle(all(X));
    cout<<count_swaps(X)<<endl;
	return 0;
}

#endif // death

/*






*/

Compilation message (stderr)

shoes.cpp: In function 'void mergeSerge(int, int)':
shoes.cpp:46:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(p<x.size())
           ~^~~~~~~~~
shoes.cpp:48:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         while(k<y.size() && y[k]<x[p])
               ~^~~~~~~~~
shoes.cpp:55:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(k<y.size())
           ~^~~~~~~~~
shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:64:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<a.size();i++)
                 ~^~~~~~~~~
shoes.cpp:71:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<a.size();i++)
                 ~^~~~~~~~~
shoes.cpp:71:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for(int i=0;i<a.size();i++)
     ^~~
shoes.cpp:81:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  A=a;
  ^
shoes.cpp:91:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<a.size();i++)
                 ~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15