Submission #143999

#	Time	Username	Problem	Language	Result	Execution time	Memory
143999		davitmarg	Arranging Shoes (IOI19_shoes)	C++17	10 / 100	54 ms	16380 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;
int n,id=1,used[100005];
vector<int> a,en[100005];

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,res;

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

    int p=0,k=0;
    while(p<x.size())
    {
        while(k<y.size() && y[k]<x[p])
        {
            ans+=x.size()-p;
            res.PB(y[k++]);
        }
        res.PB(x[p++]);
    }
    while(k<y.size())
        res.PB(y[k++]);

    for(int i=l;i<=r;i++)
        a[i]=res[i-l];
}

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;
            used[en[-a[i]].back()]=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;
        }

    mergeSerge(0,2*n-1);
    return ans;
}

#ifdef death

int main()
{
    int N;
    cin>>N;
    N*=2;
    vector<int> X;
    for(int i=0;i<N;i++)
    {
        X.PB(0);
        cin>>X.back();
    }
    cout<<count_swaps(X)<<endl;
	return 0;
}

#endif // death

/*

3
-2 2 2 -2 -2 2


*/

Compilation message (stderr)

shoes.cpp: In function 'void mergeSerge(int, int)':
shoes.cpp:45:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(p<x.size())
           ~^~~~~~~~~
shoes.cpp:47:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         while(k<y.size() && y[k]<x[p])
               ~^~~~~~~~~
shoes.cpp:54:12: 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:65:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<a.size();i++)
                 ~^~~~~~~~~
shoes.cpp:72:18: 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: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15