EXP737 C++

#include <bits/stdc++.h>

using namespace std;

int n,a[100000],imin,imax;

void nhap()
{
    cin>>n;
    for(int i=1;i<=n;i++) cin>>a[i];
}

void tim_min()
{
    imin=1;
    for(int i=1;i<=n;i++)
        if(i%2==1&&a[i]<a[imin]) imin=i;
}

void tim_max()
{
    imax=2;
    for(int i=2;i<=n;i++)
        if(i%2==0&&a[i]>a[imax]) imax=i;
}

void doi_cho()
{
    int tam=a[imin];
    a[imin]=a[imax];a[imax]=tam;
}

long long tinh_tong()
{
    long long s=0;
    for(int i=1;i<=n;i++)
        if(i%2==1) s=s+a[i];
        else s=s-a[i];
    return s;
}

void giai()
{
    long long s1=tinh_tong();
    //cout<<s1<<endl;
    tim_min();
    //cout<<imin<<endl;
    tim_max();
    doi_cho();
    //for(int i=1;i<=n;i++) cout<<a[i]<<" ";
    //cout<<endl;
    long long s2=tinh_tong();
   // cout<<s2<<endl;
    if(s1>s2) cout<<s1;
    cout<<s2;
}

int main()
{
    freopen("exp737.inp", "r", stdin);
    freopen("exp737.out", "w", stdout);
    nhap();
    giai();
    return 0;
}