C++ :

#include <iostream>
#include <cmath>
using namespace std;
int main()
{
    int a[100000],i,j=0,k=0,l=0,n;
    cin>>n;
    for(i=1;i<=n;i++)cin>>a[i];
    for(i=1;i<=n;i++)
    {if((i%2)==0)l=l+a[i];
    else k=k+a[i];
    }
    j=abs(k-l);
    cout<<k<<endl<<l<<endl<<j<<endl;
    return 0;
}

Python :

# coding=utf-8
N=int(input())
mylist=[]
i=1
while(i<=N):
    a=int(input())
    mylist.append(a)
    i=i+1
#print(mylist)
jihe=0
ji=0
ouhe=0
ou=1
while(ji<len(mylist)):
    jihe=jihe+mylist[ji]
    ji=ji+2
print(jihe)
while(ou<len(mylist)):
    ouhe=ouhe+mylist[ou]
    ou=ou+2
print(ouhe)
if(jihe>ouhe):
    print(jihe-ouhe)
else:
    print(ouhe-jihe)